
Class 
Book. 



L_B^\^&i. 



CopyrightN^ 






Cl 



COPYRIGHT DEPOSIT. 



LIBRARY OF PSYCHOLOGY AND SCIENTIFIC METHODS 

Edited bt J. McKEEN CATTELL 



EDUCATIONAL PSYCHOLOGY 



i I 



EDUCATIONAL PSYCHOLOGY 



BY 



EDWARD L. THORNDIKE 

ADJUNCT PEOFESSOR OF GENETIC PSYCHOLOGY IN TEACHERS COLLEGE, 

COLUMBIA UNIVERSITY 









> 1 J r' 



> aw 

..• ... 



NEW YORK 

LEMCKE AND BUECHNER 

1903 



LIBRARY of CONGRESS 
Two Copies Received 

JAM 26 1904 

Copyright Entry 
CLASS CL XXc. No, 



COPYEIGHT, 1903 

By EDWARD L. THORNDIKE 



. t I. c ^ *^ ^ 



* i.* * r** 



;-^_a-J 



(0 U: 



A 5 
\1^ 



!> 



PRES* OF 

THE NEW ERA PRINTINQ COMPANY, 

LANCASTER. PA. 



PKEFACE. 

This book attempts to apply to a number of educational prob- 
lems the methods of exact science. I have therefore paid no 
attention to speculative opinions and very little attention to the 
conclusions of students who present data in so rough and incom- 
plete a form that accurate quantitative treatment is impossible. 

If the book shows to any extent scientific precision and ade- 
quate statistical treatment, my thanks are due especially to the 
teaching of Professors James McKeen Cattell and Franz Boas, to 
the writings of Dr. Francis Galton and Professor Karl Pearson, 
and to the personal influence of Dr. P. S. Woodworth. 

For help in the collection of the material for the studies by my 
students or myself which are quoted, I have to thank generous and 
efficient friends, whose names make up a long list. Among them 
are: 

W. H. Maxwell, Superintendent of Schools of New York City, 
Professor Joseph Jastrow, of the University of Wisconsin, 
Professor E. G. Dexter, of the University of Illinois, 
Professor Arthur Allin, of the University of Colorado, 
Professor C. E. Seashore, of the University of Iowa, 
Miss Naomi Norsworthy, Tutor in Psychology at Teachers College, 
Miss Jeannette F. Seibert, Assistant in Psychology at Teachers College, 
Mr. L. W. Cole, Instructor in Psychology, Oklahoma University, 
Mr. W. A. Fox, Superintendent of Schools, Albion, Indiana, 
Mr. H. A. Ruger, of Columbia University, 
Miss Rosalie Pollock, Salt Lake City, Utah, 

Miss Almina George, State Normal School, Warrensburg, Missouri, 
Miss Edith McLeod, State Normal School, San Diego, California, 
Those of my students whose names appear in special connections through- 
out the book and the following principals of schools: 
Miss Julia Richman, New York City, 
Miss Caroline E. Hoefling, New York City, 
Miss Elizabeth S. Harris, New York City, 
Mr. James S. Morey, New York City, 
Mr. John A. Loope, New York City, 
Miss Christine McKernan, Jersey City, 
Mrs. Josephine Hermans, Kansas City, 
Miss Alice Hamblin, Minneapolis, 
Mr. W. I. Bray, ClifTside, 
Mr. F. E. Converse, Beloit. 



Digitized by the Internet Archive 
in 2011 with funding from 
The Library of Congress 



http://www.archive.0rg/details/educationalpsychO4thor 



CONTENTS. 

Chapter. Page. 

I. Introduction 1 

II. The Measurement of Mental Traits 3 

III. The Distribution of Mental Traits 13 

IV. The Relationships between Mental Traits 23 

V. Original and Acquired Traits 40 

VI. The Inheritance of Mental Traits 47 

VII. The Influence of the Environment 66 

\yill. The Influence of Special Forms of Training upon More Gen- 
eral Abilities 80 

IX. The Influence of Selection 94 

X. Changes in Mental Traits with Age 97 

XI. Sex Differences in Mental Traits 110 

XII. Exceptional Children 121 

XIII. The Relationships of Mental and Physical Traits 142 

XIV. Broader Studies of Human Nature 152 

XV. Conclusion. The Problem of Education as a Science 163 

Appendix. 

I. Explanatory Index of Tests 165 

II. Explanatory Index of Common IVIeasures 166 

III. Suggestions fob Investigations in Educational Science 169 

Index 175 



Vll 



CHAPTER I. 

INTEODUCTION. 

The knowledge of human nature whicli psychology offers to 
students of educational theory and practice may be roughly di- 
vided into four parts. A body of general knowledge about in- 
stincts, habits, memory, attention, interests, reasoning, etc., finds 
place in the ordinary text-books. Detailed descriptions of the 
thoughts, feelings and conduct of children at different ages are 
available in the literature of child study. Particular facts which 
bear upon this or that school subject or method of teaching may 
be gleaned from researches upon perception, association, practice, 
fatigue and other topics. Finally there is an even more inco- 
herent mass of facts about the influence of ^ inheritance, environ- 
ment and general mental development, the beginnings of what we 
may call a general Mynamic psychology, which are relevant to 
many of the broader questions of education. It is the aim of 
this book to put this last group of facts at the service of students. 

That they have thus far gone without systematic and conven- 
ient exposition is due to the complexity of the problems involved, 
not to any doubt concerning their practical importance. Wliat 
we think and what we do about education is certainly influenced 
by our opinions about such matters as individual differences in 
children, inborn traits, heredity, sex differences, the specialization 
of mental abilities, their inter-relations, the relation between them 
and physical endowments, normal mental growth, its periodicities, 
and the method of action and relative importance of various envi- 
ronmental influences. For instance, schemes for individual in- 
struction and for different rates of promotion are undertaken 
largely because of certain beliefs concerning the prevalence and 
amount of differences in mental capacity; the conduct of at least 
two classes out of every three is determined in great measure 
by the teachers' faith that mental abilities are so little specialized 
that improvement in any one of them will help all tlie rest; man- 
ual training is often introduced into schools on the strengtli of 

1 



2 EDUCATIONAL PSYCHOLOGY 

somebody's confidence that skill in movement is intimately con- 
nected with efficiency in thinking ; the practical action with regard 
to coeducation has been accompanied, and doubtless influenced by 
arguments about the identity or the equality of the minds of men 
and women; the American public school system rests on a total 
disregard of hereditary mental differences between the classes and 
the masses; curricula are planned with some speculation concern- 
ing mental development (e. g., the culture epoch theory) as a guide. 
It is thus easy to find cases where educational practice depends 
upon opinions about our group of topics. It is still easier to note 
a similar dependence in the case of educational theory. Abund- 
ant illustrations will appear in the course of our study of the topics 
themselves. 

These and their order will be: — 

The measurement of mental traits. 
_ The distribution of mental traits. 

The relationships between mental traits. 
-^- Original and acquired traits. 

- Mental inheritance. 

" The influence of the environment. 

:- The influence of special training upon general abilities. 

- The influence of selection. 

The development of mental traits with age. 

Sex differences. 

Exceptional children; mental and moral defectives. 

The relationships of mental and physical traits. 

Broader studies of human nature. 



CHAPTER II. 

THE MEASUREMENT OF MENTAL TRAITS. 

The work of education is to make changes in human minds 
and bodies. To control these changes we need knowledge of the 
causes which bring them to pass. Such knowledge necessitates 
some means of measuring mental and bodily conditions ; adequate 
knowledge necessitates accurate and complete measurements. We 
do all make measurements of mental as well as of bodily condi- 
tions, but commonly our measurements of mental conditions and 
so of the changes due to any educational endeavor are crude, indi- 
vidual and incomplete. The introduction of a new method, say 
of teaching arithmetic, is followed by A's statement that the class 
learned ' more,' B's that they learned perhaps no more, but ob- 
tained 'better' training. A and B have both made measure- 
ments of the conditions under the old and under the new method, 
but they were so rough that the comparison gave only the result 
'more' or 'better' with no precise statement of how much. 
Moreover their measurements were taken by the instrument of 
individual opinion, so that C and D are at liberty to flatly deny 
the result. Finally they left unmeasured the subtler conditions 
of permanent interest, the rates of returns to time and effort spent, 
etc. ^ An adequate measurement of mental traits will be one that 
is precise enough for us to draw the conclusions we desire, objec- 
tive or subject to identical repetition by another observer, and 
complete enough to take in all the features of the condition that 
are important for our purpose. 

If we could make such adequate measurements exhaustively 
we could describe a man's mind as so many units of that emotional 
tendency, so many of this sense power and so on through a well- 
nigh interminable list of possible mental traits. We should then 
be able to state exactly the difference between any two human 
beings, between the condition of anyone before and after any 
course of study or other educational influence ; we could compare 
the results of different systems of education, describe the changes 

3 



4 EDUCATIONAL PSYCHOLOGY 

due to maturity or calculate the personal efficiency of different 
teachers. In the instance just quoted A could say : " The 600 chil- 
dren in my school under the old method made an average gain of 
4 per cent, in a year in arithmetical knowledge, 3 per cent, in 
interest and zeal, etc. Under the new method the figures are 6 
per cent., 7 per cent., etc." 

To some extent we can already make accurate objective meas- 
urements of mental traits. We can measure the ability to add 
or to spell or to translate Latin or to discriminate colors as accu; 
rately though not by any means as easily as we can height or 
weight. We can use units of time taken, errors made, facts re- 
membered and such like as well as inches or ounces. 

For instance the number of A's marked in a minute on a 
blank like the one reproduced below gives a measure of a certain 
complex ability in perception which is capable of the same treat- 
ment as any physical measurement. 

OYKFIUDBHTAGDAACDIXAMRPAGQZTAACVAOWLYX 

WABBTHJJANEEFAAMEAACBSVSKALLPHANENPKAZF 

YKQAQEAXJUDFOIMWZSAUCGVAOABMAYDYAAZJDAL 

JACINEVBGAOFHAKPVEJCTQZAPJLEIQWNAHKBUIAS 

SNZMWAAAWHACAXHXQAXTDPUTYGSKGEKVLGKIM 

FUOFAAKYFGTMBLYZIJAAVAUAACXDTVDACJSIUFMO 

TXWAMQEAKHAOPXZWCAIRBEZNSOQAQLMDGUSGB 

AKNAAPLPAAAHYOAEKLNVFAEJAEHNPWIBAYAQRK 

UPDSHAAQGGHTAMZAQGMTPNUEQNXIJEOWYCEEJD 

UOLJCCAKSZAUAFEEFAWAFZAWXBAAAVHAMBATAD 

KVSTVNAPLILAOXYSJUOVYIVPAAPSDNLKEQAAOJLE 

GAAQYEMPAZNTIBXGAIMEUSAWZAZWXAMXBDXAJZ 

ECNABAHGDVSVFTCLAYKUKCWAFEWHTQYAFAAAOH 

Often, however, it seems impossible to find any unit of amount. 
For instance, how much more fear has a very timid child than a 
very bold one, or just how much greatness as a writer had Shak- 
spere, or to just what quantity of what do we refer when we think 
of a certain boy's 'badness' ? Although we are thus unable in 
many cases to describe a mental trait as so much of such a thing, 
yet it is clear that we still do make measurements in these cases. 
We measure not by units of amoimt but by relative position in a 
group. The timid child we measure as being more timid 



THE MEASUREMENT OF MENTAL TRAITS 5 

than 9 out of 10 children; Shakspere as being better than 
99,999,999 out of 100,000,000 in greatness as a writer; the boy 
as being worse than the average. Such measurements may be as 
definite and precise and instructive as the more familiar kind. 
If we know that a boy who was the worst in a thousand has by 
training become not distinguishable from the average we know 
the change in him and the value of the training as well as we do 
in the case of a gain of 10 pounds in weight, or a reduction of 
20 per cent, in errors in a certain amount of addition. 

It is also often possible on the basis of facts presently to be 
described to turn a measurement in terms of relative position into 
a measurement in terms of units of amount. In fact measure- 
ments of mental traits can be made and are being made that are 
as much superior to individual opinions as a measurement by a 
millimeter rule is to a guess by the unaided eye or as a physician's 
count of the red blood corpuscles is to a statement that a person 
looks pale. 

One peculiarity of measurements of mental traits deserves 
special notice, their variability. Physical measurements too are 
variable. If we measure the length of a wire or the height of a 
man or the weight of a stone we get at different times slightly 
different amounts, and physicists use an elaborate system of cal- 
culation to get from a group of varying measures the one measure 
that most probably represents the fact. The marked variability 
of mental measurements is then not a barrier to accurate treat- 
ment of mental traits, but it does make necessary certain precau- 
tions in measuring them. These are : 

1. Repeated measurements in order to estimate from varying 
results the true status. 

2. An expression of the abilities shown by all these measure- 
ments together, or at least 

3. An expression of the essential features of the ability. 
For instance A was tested by having a series of 12 letters read 

at a rate of 2 per second, he being required to write down as 
many as he could remember and in tlieir proper order as soon as 
the reading was finished. He made a score of 6. This measure- 
ment is so far so good. It is better to believe that A's ability in 
the test is 6 than to giiess at it, l)iit l\y giving a second test the 



6 EDUCATIONAL PSYCHOLOGY 

score was 8. To saj that A's ability is 6 or 8 or averages 7 is 
better than to have taken the 6 as a measure. But further trials 
give (including these two) 

1 record of 4 correct. 



4 records 


" 5 


4 


" 6 


7 


" 7 


13 


" 8 


3 


" 9 


4 


" 10 



Trom all these scores we get as an average 7.94 words correct, 
calling a record of 4, which of course means from 4 up to 5, 4l/2> 
one of 5, 51^, etc. We get as the score above and below 
which an equal number of trials lie (median) 8.15 ; and as the 
most common record (the mode) 8.5. I^ow the trustworthiness 
of any one of these is 6 times as great as that of the first single 
score 6.* Clearly we cannot be sure that the average of the 36 
measurements is identical with A's true average ability. In fact 
we can be almost sure that it is not. 72 measurements might give 
and almost certainly would give, a slightly different average. 
True average ability in the case of variable measurements means 
the measure we would get as an average or median or mode (ac- 
cording to the type we desire to ascertain) from an infinite number 
of measurements. Only by chance will the result from any finite 
number of measurements be identical with it. All our measures 
represent approximations, but the greater the number of measures 
the closer the approximation will be. 

■ This series of measures is our knowledge of A's ability. We 
can see the fact more clearly by expressing it in space rather than 
in figures. If we let each quarter inch along a horizontal line stand 
for one degree of ability, and each one tenth inch of height above 
it stand for one manifestation by A of the ability designated by 
that place, we have figure 1, by which one can see at a glance A's 
ability, its variability and his general tendency to keep nearer 8 
than any other one ability. 

* It is found in variable measurements of the ordinary sort that the 
reliability of an average result increases as the square root of the number 
of measurements taken. 



THE MEASUREMENT OF MENTAL TRAITS 



If we must for any reason abbreviate our description of A's 
ability we may best take two measures, one of the ability about 
which his various scores center most closely and the other of the 
closeness of this grouping. We may term these the center of 
gravity and the variability. For the former the average or me- 
dian or mode may be used, for the latter the average of the differ- 
ences between the individual records and their center of gravity 
(Average Deviation or A.D.). 



"FtS-l 



rcq.!l 



_r 



H S 6 7 8 f JO Uttrs T^calUi. 

Fig. 1. 



Fig. 2. 



Other measurements of the latter that are better for many 
purposes are the square root of the average of the squares of all 
these differences (standard deviation, deviation of mean square, 
a) and the difference less than which are 50 per cent, of the dif- 
ferences (probable error, P.E. or ^). In the case of our illus- 
tration A.D. (reckoned from the mode) ^1.17. This feature of 
A's ability is for many purposes just as important as its center 
of gravity. 

Let us suppose that with the same test B showed instead of 
the measures given above the following ability : 

2 records of .5 correct. 

3 " 6 " 
11 " 7 " 
17 " 8 " 

3 " 9 " 

This is shown graphically in figure 2. The average, median 
and mode would be closely the same as before, but the variability 
of the measures would be less. The limits before were 4—10. 



8 EDUCATIONAL PSYCHOLOGY 

jSTow they are 5-9. The average difference of the individual 
measures from the mode was 1.17. ]^ow it is 0.7. B's ability 
has the same center of gravity as A's, but B is a more constant 
performer. 

It is obvious that an average from a set of measurements like 
the second is less likely to deviate from the true status than an 
average from a set like the first. And in general the less the 
variability of the single measures the greater the reliability of 
the result inferred from them. In point of fact, with such meas- 
ures as one ordinarily obtains, the probable difference of the result 
obtained from the true status of the trait in question is directly 
proportional to the variability of the measures and inversely pro- 
portional to the square root of their number. 

In the case of A's memory we should say, using formulas the 
derivation of which need not be described here: From what 
knowledge we have, the most likely true average ability for A is 
7.9; the chances are 

1 to 1 that the true average does not differ from 7.9 by more than .171 

2 to 1 that the time average does not differ from 7.9 by more than .245 

3 to 1 that the true average does not differ from 7.9 by more than .291 
99 to 1 that the true average does not differ from 7.9 by more than .651 

999 to 1 that the true average does not differ from 7.9 by more than .835 

This multiplication of measurements and consequent calcula- 
tion may seem a bit far-fetched and complicated, but it is only 
what is common in the exact sciences and is well worth the trouble. 
Any measurement of a mental trait should be accompanied by a 
statement of its reliability, i. e., of the probable deviation from 
the true ability. Measurements of mental traits without such a 
statement, or in its place such an account of the number of meas- 
ures and their variability as would enable us to calculate it, should 
be received with skepticism. 

Educational science more often uses measurements of groups, 
such as children of a given age or men characterized by certain 
training or individuals of a defined class. Here again we shall 
find that additional thought in arranging the facts and devising 
numerical expressions of them will be profitable. As a sample 
group measurement, let us take the ability found in twelve-year- 
old boys in school in the case of the following test: To mark as 



TEE MEASUREMENT OF MENTAL TRAITS 9 

many as possible of the words containing the two letters a and t 
in the page reprinted below; 120 seconds being allowed for the 
work. 

A. 

Dire tengo antipatia senores; esto seria necedad, porque hombre vale 
siempre tanto como otro hombre. Todas clases hombres merito; resumidas 
cuentas, sulpa suya vizxonde; pero dire sobrina puede contar dote veinte 
cinco duros menos, tengo apartado; pardiez tamado trabajo atesorar-los para 
enriquecer estrano. Vizconde rico. Mios, quiero ganado sudor frente saiga 
familia; suyo, pertenence, tendrari. Conozco marido pueda eonvenirle Isa- 
bel: Carlos, sobrino. Donde muchacho honrado, mejor indole, juicioso, vali- 
ente? Quieres sobrino. Esposo parece natural, pero. Pero, pero, diablos 
objeciones hacer. Posible quedandonow solos siempre hacer oposicion. Solo 
delante hentes eres ministerial. Pues, sidens siempre plan, dicho antes, 
porque hace tiempo notade cose aflige cierto. Sabes cuante quiero Carlos ; 
consuelo apoyo; despues persona quiero mundo. Como eres buena amable, 
quieres porque, darme gusto, pero quisiera. Palabra cuesta trabajo; parece 
sino teines miedo agasajarle, manifestarle carino. Veces tratas cumplimiento 
veces senor. Probare; ejemplo pudiendo abandonar case negocios, deseaba 
hubiese acompanado viaje; preferiste sola sobrina doncella. Quise contra- 
decir, pero para sentimiento, para tambien. Voto gasta palabra, dice frases, 
dice; pero alia adentros quiere. Mientras estado malo, puesto dirigir casa; 
pardiez aunque carrera, hacia mejor; cabo tiene sobre ventaja poca edad, 
actividad zelo, pues para contigo digo. Siempre ordenes; dejaria matar 
alcanzarte billete para opera para baile. Necsitamos para felices; algo 
estrano, desconocido. Esta resuelto; supuesto hemos hablado esto, niismo 
precise empieces darle conocer nuestros planes. Quien mejor. Opone nunea 
deseos, sera facil nadie persuadirle. Probare menos, precise sino creere tienes 
interes decidido proteger vizconde. Pudieras creer siempre inclinado senores 
cabra tira monte. Pero tengo nada ellos esposo tienes siempre pensativo 
siempre trists. Diablos tiene Carlos acereate, tiene hablarte. Hola parece 
sacado letargo tengo algunas instrucciones cajero marcha dentro poco. 
Para empresa piensa usted establecer Habana. Precisamente bonita especu- 
lacion bien manejada sobro todo. Espero pero tengo entre manos etro 
proyecto interesa aqui estabamos ocupando pienso. Eres porque quieres 

B. 
porque e tregas defensa peligro lugar huir mujer, liarto debil duda pero 
algun desgracia tuviese luchar sentimientos seniejantes tuyos, lejos ceder ellos 
cobardemente moriria pero triunfaria. Tendras menos valor tendre darte 
lecciones valor energia. Vamos, Carlos, amigo creemc sentimiento, profundo 
razon pueda subyugar, desgracia grande pueda soportar veneer nuestro cora- 
zon. Ofrezco apoyo eres creo sequiras consejos. Bien, hable usted. Quiere 
casarte Isabel. Isabel, prima imposible; quiere otro, vizconde amigo. Precise 
persiiadirselo hare etros partidos habra jamas para jurado nada espero pero 
consei-\'are siempre entero este amor ella ignora unos juramentos recibido. 
Enhorabuena otro micdio ascquarara tranquilidad, uya destine ofrecido aleja 
Madrid, precise aceptarle. Privarme presencia felicidad hecho usted para 
censeje especie embargo precise seguirle solo puedes conservar amistad clige. 



10 



EDUCATIONAL PSYCHOLOGY 



Jamas caballero crei usted digno consejos dejo usted abandonado mismo nada 
tango decirle Carlos aleja, echa mirade salir Dona mira; suspira sale. 
Porque inquieta partida desterremos para siempre memoria quiero puedo 
presente temo; ausente, echo menos, verle sonrojo, nombre hace temblar. 
Embargo nunca dicho debiera ignorarlo Dios Dame fuerzas para resistir. 

165 boys were tested and to each was given a measure ; namely, 
the number of words containing a and t that he marked.* The 
detailed results for the group are : 



3 words were correctly marked by 1 boy 


4 ' 




' " 3 boys 


5 ' 




" 1 boy 


6 ' 




' " 3 boys 


7 ' 




" 4 < 




8 ' 




« 4 ' 




9 ' 




" 10 ' 




10 ' 




" 13 ' 




11 ' 




" 13 ' 




12 ' 




" 18 ' 




13 ' 




" 16 ' 




14 ' 




" 9 ' 




15 ' 




" 15 ' 




16 ' 




" 20 ' 




17 ' 




" 10 ' 




18 ' 




« 6 ' 




19 ' 




" 7 ' 




20 ' 




" 3 ' 




21 ' 




" 1 boy 


22 ' 




' " 2 boys 


23 ' 




« 2 " 


24 ' 




" 2 " 


25 ' 




" " 


26 ' 




" 2 ' 


i 



We call the number of individuals who receive any single 
measure the frequency of that measure or degree of ability in the 
group. Thus 1 is the frequency of the measure 3, 3 of 4, 1 of 
5, 3 of 6, etc. The detailed results just given are then a table 
of the frequencies of the different measures or degrees of the trait 
in the group, 12-year-old boys. They give the distribution of the 
trait in the group. Such a total distribution or table of fre- 
quencies is the true measure of the trait in the group, and any 

* In reality four others took the test but misunderstood its require- 
ments. For simplicity's sake I confine the illustration to the measurement 
of the trait in 12-year-old boys who understood the test. 



TEE MEASUREMENT OF MENTAL TRAITS 



11 



average or other simple numerical expression should be regarded 
as an effort to present briefly the most essential feature of the real 
fact, not as an adequate equivalent of it. By a diagram the true 
measure of the trait in the whole group can be realized as quickly 
as can a single average. We 
may picture the frequencies of 



fl 



f 



Kq.J 



JUL 



31Ji7ttt 



^n 



15 
Fig. 3. 



25 



the different grades of ability in 
the group of varying individuals 
just as in figures 1 and 2 were 
pictured the frequencies of the 
different grades of ability in 
the varying trials of the same 
individual. 

Figure 3 thus presents to a 
single glance (as soon as we un- 
derstand the method of its construction) our entire table of page 
10. Such a graphic measurement of a trait in a group is called 
the surface of frequency of the trait. 

The two more important features of a measurement of a 
gToup of individuals are its center of gravity or the general tend- 
ency of the trait, and its variahility. The case of a group of 
varying individuals is statistically identical with that of a group 
of varying performances by an individual. 

In our illustration the average ability of the group is 14.06,* 
the median ability is one fifth of a grade lower (13.8), and the 
abilities 12 to 16 are much more frequently found than any other 
consecutive five. The mode might thus be taken to be 12—16. 

The variability of the group is, using the three customary 
measures : 

A.D. (average difference between any individual's ability and 
the average of the whole group) ^ 3.47. 

c (square root of the averages of the squares of the differences 
of all the individuals from the average of the group) = 4.31. 

P.E. or ^ = 3.32 (half of the individuals differed from the 
average by less than 3.32). 



* A rank of 3 really means above 3.0 and below 4.0, one of 4 means 
above 4.0 and bolow .5.0. The actual value of 3 is therefore 3.5, of 4, 4.5, 
etc. The average and median are calculated from these real values. 



12 EDUCATIONAL PSYCHOLOGY 

Besides these customary measures of the variability of a group, 
we could of course make any that seemed advisable. E. g., all 
our cases fall between 3 and 26 or inside of 2 and 27, or within 
11.06 below and 12.94 above the average; 124 cases out of 
165, or 75 per cent., fall between 9 and 17, or within 5.06 below 
and 3.94 above the averages; there are 25 individuals who differ 
from the average by from to 1, 33 by from 1 to 2, 33 by from 
2 to 3, 23 by from 3 to 4, 16 by from 4 to 5, 11 by from 5 to 6, 
etc. 

As with the separate trials of an individual, so with the dif- 
ferent individuals of a group, the average or median is only an 
approximate measure of the true condition. Its closeness of ap- 
proximation depends directly upon the square root of the number 
of cases and inversely upon their variability. There is no excuse 
for a writer's ignorance of just how reliable his measures of a 
group are. 

For our illustration, the chances are a little over 2 to 1 that 
the true average ability of 12-year-old boys will not differ from 
the average 14.06 by more than 0.235, 21 to 1 that the difference 
will not be more than 0.47, and 332 to 1 that it will not be greater 
than 0.705. Thus there is practical certainty that the average 
ability of 12-year-old boys is between 13.355 and 14.765. 



CHAPTER III. 



THE DISTRIBUTION OF MENTAL TRAITS. 

Do the distributions of mental traits in groups of individuals 
follow any regular law ? Are the differences between individuals 
in mental capacities and characteristics explainable by any simple 
set of causes and amenable to any single type of description ? If 
such uniformity exists, the exact study of educational problems 
is possible and even easy. 

It has been supposed, for more or less satisfying reasons, that 
in any group of individuals representing a single species, in re- 
spect to any trait not then in- 
fluenced by natural selection, 
the distribution would be that 
of a chance event, the surface 
of frequency being that of the 
probability integral. The exact 
meaning of this supposition and 
the basis for it need not be dis- 
cussed here. Our interest is in 
discovering whether any one 
type of distribution does charac- 
terize all mental traits in hu- 
man beings. By using graphic 
representations rather than alge- 
braic formulae the answer and 
the evidence for it can be made 






Figs. 4, 5, 6. 



clear even to one who knows nothing whatever of the mathematical 
properties of the surface of frequency of a chance event or of 
any other. 

Figure 4 gives the distribution or surface of frequency of the 
type to which perhaps all the distributions of mental traits con- 
form. Figure 5 gives the same distribution as figure 4, but with 
a coarser separation into grades. Figure 6 gives again the same 
distribution, but this time with a verv fine subdivision of grades. 

13 



14 EDUCATIONAL PSYCHOLOGY 

Our question is, "Are mental traits commonly distributed 
after the type of figures 4—6 ?" We can answer it by comparing 
with figures 4-6 figures 7-24, each of which represents the actual 
distribution found for some mental trait. To make the compari- 
son easy a light dotted line shows in each case the rough outline 
of figure 6. The reader has then simply to note how closely the 
actual distributions follow the dotted lines.* 

In drawing these surfaces the median value is made to coin- 
cide with the median value of the normal surface of frequency. 
Whenever any distribution represents measurements by different 
people or under different conditions or of different sexes or with 
different tests, it is compounded of separate surfaces each drawn 
with consideration of the mean and variability proper to the single 
group and then so combined as to allow roughly equal weight to 
the distributions from equal numbers of cases, ISTo distributions 
are thus combined unless they all individually represent the same 
type as they do when combined. Barring the inclusion in the 
same distribution of the different racial types found in schools, 
of children sometimes as much as 12 months apart in age in the 
age groups and children in the school groups as noted, there are 
no sources of the variability found save precisely those which we 
are trying to measure. The strongest proof of the approximation 
of the distribution of mental traits to the normal type is given 
by a score or more of distributions from too few cases to appear 
here which yet all follow the normal type. 

Since the aim of this section is simply to show the general 
fact of distribution, not to analyze it precisely, I have made no 
attempt to ascertain whether after all the combination of mental 
species is not present. That may well be the case, but for the 
practical pui'poses of educational science it makes little differ- 
ence. Our use of the fact of approximation to the normal type 
will be justifiable in either case. 

In all these cases there is a remarkable uniformity in the dis- 
tribution of mental traits amongst individuals. In all cases the 

* For the sake of the reader versed in statistics, I may add that the 
scale of the base line for each distribution is so arranged that the deviation 
of mean square for each one is represented always by the same length and 
the total number of cases by the same area. It is thus possible to compare 
any one with any other or with the normal frequency curve. 



THE DISTRIBUTION OF MENTAL TRAITS 



15 



At.,t 




K-T t>lX 
f* lit 



N< iro. 

M>'>iHUU.u/>i< 







J^ 



r 



N-IOQ 



T.J. 't 




Kail. I 

/ 

r- .-- - ^ 



f M. » 




R«J.(. •ttii«.V.Ui4. 
N-77. 











\ ^^% '* 







P^. ti 




K-IIL 




11,. ujj, N-i<r«L 



N.IU 





«> t. 







Iz-ITC 



Figs. 7-24. 



16 EDUCATIONAL PSYCHOLOGY 

average ability is near the common ability and both are near the 
point above which 50 per cent, of the cases lie. The greater 
number of the cases lie near the average, mode or median point, 
and degrees of ability a certain amount above or below that point 
are nearly equally common. The more remote a degree of ability 
is from the average or median or mode, the fewer are the indi- 
viduals who possess it. The difference between the degrees of 
ability above and below the average, mode or median between 
which 50 per cent, of the individuals are included is about two 
ninths of the difference between the lowest and highest degrees 
of ability found. 

This type of distribution is called the normal distribution. It 
approximates the types found for most variable organs or func- 
tions in nature in the case of any single species when the organ 
or function in question is not subject to selection. 

The so common fact of the approximately normal distribution 
of mental traits leads to many important theoretical considera- 
tions and gives many possibilities of studying human nature that 
would otherwise not exist. But for our purposes most of its re- 
sults may be neglected. For us a knowledge of the existence and 
frequency of normal distribution is of consequence first because 
it emphasizes the fact of human individual differences and gives 
us a precise idea of their amount; second, because it enables us 
to compare groups accurately. In the study of heredity, for in- 
stance, we shall compare the group 'children of parents possessing 
such and such a degree of such and such a mental trait' with 
children of parents possessing a different degree thereof. In the 
study of sex differences we shall compare the group men with the 
group women, the group 10-year-old boys with the group 10-year- 
old girls. In the study of the influence of the environment we 
shall compare 'group with such and such training' with 'group 
without it.' In the study of growth and maturity we shall com- 
pare different age groups. In all these cases we can get much 
more illuminating and precise and extensive knowledge by com- 
paring the distribution curves for the two groups than by using 
mere arithmetical averages. We shall also avoid a number of 
misunderstandings and fallacies by bearing in mind the fact of 



V. 



THE DISTRIBUTION OF MENTAL TRAITS 



17 



the variability of mental traits and the prevalence of variability 
of the normal type. 

The meaning of cases where the distribution of mental traits 
does not follow the normal frequency curve will become clear if 
we examine, first, some cases of the distribution of a trait in a 
group of individuals of two or more distinct species and, second, 
cases where some selective agency has been at work. 














Figs. 25-HO. 



Figure 25 gives the distribution of ability in the test in mark- 
ing A's of a group of children 8, 9, 14 and 15 years old. From 
figure 26, which gives separately the distributions (1) for those 
8 and 9, and (2) for those 14 and 15, we see clearly that the pecul- 
iar flattening of figure 25 is due to the mixture of two species 
each of which approximates fairly to the normal type. The same 
result of mixture is shown even more emphatically by figure 27, 
which gives the distribution of a group composed of about 140 
third grade and about 180 seventh grade girls. Here the two 
modes belonging to the two grades are easily distinguishable. A 
real case of the same sort of distribution is pictured in figure 28, 
which gives the distribution of strength of arm in human adults. 



18 



EDUCATIONAL PSYCHOLOGY 




Ti 7> ir It II 







"The two species here are men and women.* When we find in 
the surface of frequency of a mental trait a departure from the 
normal toward a lowering and broadening of the surface or toward 

two or more modes we may com- 
monly expect to find a mixture 
of species. Other illustrations 
of such a condition are given in 
figures 29 and 30. 

Figure 31 gives the distribu- 
tion in a test of controlled associ- 
ation of the 12-year-old boys in 
the 6A grade or higher. The lack 
of symmetry in the surface is 
obviously due to the fact that wef 
are dealing with a selected group ; 
that the duller and less mature 
boys have been eliminated. The 
influence of the opposite sort 
of elimination is seen in figure 
32, which gives the distribu- 
tion in the same trait of 12-year-old boys in the grades lower than 
the 6 A. By combining the two we should have a normal fre- 
quency surface. Figure 33 gives a real case of a distribution 
distorted by selection comparable to those artificially produced in 
our examples. It is the distribution of mathematical ability in 
the candidates for honors in mathematics at Cambridge Univer- 
sity, f Of course such candidacy implies that the poorer grades 
of mathematical ability are eliminated. Any selective agency 
which works upon a species of individuals will alter the shape of 
the surface of frequency for any mental trait unless its selections 
are random with respect to different amounts of that trait. As 
the selective action is commonly such as picks out the good or the 
bad, the result is conmionly to produce a 'skewness' of the surface 
toward one extreme and a blunted condition at the other. When 
a series of measurements in a group shows a deviation from the 

* Drawn roughly from the data given in Gallon's ' Natural Inheritance,' 
p. 200. 

t It is taken from Gallon's ' Hereditary Genius,' 2d ed., p. 16. 



Figs. 31-33. 



TEE DISTRIBUTION OF MENTAL TRAITS 



19 





TCi-is- 



Figs. 34-35. 



m-rt. 



y.vs* 



n 



normal law of frequency toward conditions like those in figure 
34 and figure 35, it will be wise to look for some selective agency 
at work upon the group. If the 
approximately normal distribu- 
tions figured above are exam- 
ined carefully a slight elimina- 
tion of the least efiicient will be 
apparent. This is probably due 
to the fact that children who are 
very low in a scale of intelli- 
gence are eliminated from the 
public schools altogether and so 
are not represented in our tests. 
Figures 36, 37 and 38 present other samples of asymmetrical dis- 
tributions due to selection. 

It is likely that the statistics 
upon which were based the fre- 
quency surfaces on page 15 
=* are slightly influenced by both 
mixture of species and selec- 
tion, and that without these they 
would approximate still closer to 
the one simple law, and support 
still more emphatically the hy- 
pothesis that the distribution of 
any mental trait in a homogene- 
ous species undisturbed by selec- 
tion is that given by the proba- 
bility integral. 
From this hypothesis, two important results follow. The 
measurement of a mental trait 
in a group does not, when distri- 
bution is normal, require the com- 
plete statement of the distribu- 
tion, since from knowledge of the 
average or median or mode and 

of the A.D. or some other measure of the variability of the group 
about the average we can reconstruct approximately the entire dis- 



tA**4 ^•«AUm 



ft" J, 31 



n 



tl-fX 




£JL 



TiV St 



f^ R 



Figs. 36-38. 




8 1 (0 M i: 13 II If 16 iTc 

Fig. 39. 



20 EDUCATIONAL PSYCHOLOGY 

tribution scheme. Thus given the facts that the average ability 
of 12-year-old boys in a test of memory is 17.5 and that the 
standard deviation is 3.0, and we know that the whole distribu- 
tion scheme for 12-year-old boys in the test is that of figure 39 
and table I. The mathematical formulse by which this is done 

need not concern us here. 

TABLE I. 





Percentage of cases 




Percentage of cases 


)ility. 


possessing it. 


Ability. 


possessing it. 


8 


.1 


18 


13.1 


9 


.3 


19 


11.7 


10 


.6 


20 


9.4 


11 


1.3 


21 


6.7 


12 


2.5 


22 


4.3 


13 


4.3 


23 


2.5 


14 


6.7 


24 


1.3 


15 


9.4 


25 


.6 


16 


11.7 


26 


.3 


17 


13.1 


27 


.1 



The other result is that if we know that distribution is regular 
and have given the measurements in terms of relative position of 
a large number of individuals chosen at random, we can turn 
those measurements into terms of amount. Here again the mathe- 
matical formulae are best omitted. The reader may take it on 
trust that such a transposition as the following is correct. 

Given the knowledge that 1,000 individuals rank in order of 
excellence in English composition as follows: 

Individuals 1- 2 are indistinguishable in ability but better than any 

below. 
3- 5 are indistinguishable in ability but better than any 

below and worse than any above. 
6- 10 are indistinguishable in ability but better than any 

below and worse than any above. 
11- 20 are indistinguishable in ability but better than any 

below and worse than any above. 
21- 40 are indistinguishable in ability but better than any 

below and worse than any above. 
41- 70 are indistinguishable in ability but better than any 

below and worse than any above. 
71- 120 are indistinguishable in ability but better than any 

below and worse than any above. 
121- 280 are indistinguishable in ability but better than any 

below and worse than any above. 
281- 720 are indistinguishable in ability but better than any 
below and worse than any above. 



TEE DISTRIBUTION OF MENTAL TRAITS 



21 



Individuals 721- 880 are indistinguishable in ability but better than any 

below and worse than any above. 

881- 920 are indistinguishable in ability but better than any 

below and worse than any above. 

921- 960 are indistinguishable in ability but better than any 

below and worse than any above. 

961- 984 are indistinguishable in ability but better than any 

below and worse than any above. 

985- 993 are indistinguishable in ability but better than any 

below and worse than any above. 

994- 997 are indistinguishable in ability but better than any 

below and worse than any above. 
998-1000 are worse than any above. 

and given the knowledge that the distribution in this ability is 
regular. Take as the ability in composition above and below 
which half of the individuals lie, and as 1 the ability excelled by 
152 of the group and as — 1 the ability less than which 152 of 
the class have. Then the scheme of distribution is that of table II. 



TABLE II. 

Highest 2 rank between + 2.87 and probably + 3.00, perhaps more. 
Next 3 

5 
10 
20 
30 
50 
160 
440 
160 
40 
40 
24 
9 
4 
3 

From this scheme we can get a measure in amount for any 
individual whose position compared with the rest is knoAvn. For 
instance the ability of individual 4 is close to -f- 2.44, that of indi- 
vidual 17 is close to -\- 2.17, while that of individual 33 is 
-f- 1.88. No. 4 is nearly 30 per cent, farther above the average 
than ]^o. 33. In this scheme of course we do not so far know 
just what 1.0 or 1.5 or any other measure represents. -|- 2.98 
may be the ability of Shakspere or of a fairly good high school 



+ 2.575 




+ 2.87 


averaging close to + 2.7 


+ 2.325 




+ 2.575 


(( 


" + 2.44 


+ 2.05 




+ 2.325 


ie 


" + 2.17 


+ 1.75 




+ 2.05 


it 


" + 1.88 


+ 1.475 




+ 1.75 


a 


etc. 


+ 1.18 




+ 14.75 






+ 0.58 




+ 1.18 






+ 0.58 




— 0.58 






— 0.58 




— 1.18 






— 1.18 




— 1.405 






— 1.405 




— 1.75 






— 1.75 




— 2.145 






— 2.145 




— 2.53 






— 2.53 




— 2.74 






— 2.74 




probabl}- 


— 3.00, 


perhaps less. 



22 EDUCATIONAL PSYCHOLOGY 

composition according to the group of 1,000 we are studying. But 
if we give a few samples of the compositions with the amounts 
assigned we make the hitherto arbitrary unit of amount a per- 
fectly definite thing, as definite as an inch or an ohm or kilogram. 
Our study of the distribution of mental traits thus provides us 
with a means of accurately measuring such physical traits as color 
of eyes or hair and such mental traits as courage, honesty, ambi- 
tion or eminence, provided we deal with homogeneous groups and 
have reason to think that the distribution of the ability in the 
group studied is normal. 

The reader will, I trust, have inferred already two corollaries 
of the law of distribution : the first that small differences between 
individuals in the same species are far more common than larger 
ones, the second that within any one species there is no clear 
demarcation of ordinary from exceptional grades of ability. It 
is a common error to distort the truth that in any school grade 
or at any age there are great differences in ability between the 
extremes in any mental trait into the error that such great differ- 
ences are as much the rule as lesser ones. The inference is drawn 
that teaching which is adequate for say one third the range of 
abilities found would be adequate for only one third of the stu- 
dents. On the contrary such teaching would be adequate for over 
two thirds of the students, for over two thirds of the individuals in 
any homogeneous group are centered within the middle third or 
less of the total range of ability. 

Again it is a common error to imagine that nature has pro- 
vided distinct classes corresponding to our distinct words, e. g., 
normal and abnormal or ordinary and exceptional. But within 
any natural group grades of amount of any trait seem to be con- 
tinuous. Genius and idiot, precocious and retarded, musical and 
unmusical, bright and dull and all the host of descriptive words 
do not mark off distinct varieties of beings, but artificial sections 
of a continuously varying group. The realization of this fact 
will prevent a multitude of errors in arguments about the processes 
and results of education. 



CHAPTEK IV. 

THE EELATIONSHIPS BETWEEN MENTAL TEAITS. 

We may expect that knowledge of the relations between men- 
tal traits will outvalue knowledge of the traits themselves. If an 
alteration in one function involves some alteration in others, our 
knowledge of the condition of the first function is made far more 
fruitful. Moreover its own nature and means of control may be 
best known through its relationships. 

Amongst educational problems that are essentially problems 
concerning mental relationships are the following: The disci- 
plinary value of studies; the arrangement of groups of electives 
in a curriculum ; systems of grading and promotion ; tests of men- 
tal growth and condition. 

The extent to which the training of any one mental function 
secures improvement or better chances for it in other functions 
depends upon the closeness of relationship between the functions 
in question. If, for instance, the ability to notice errors in arith- 
metic is directly correlated with the ability to notice errors in 
spelling, then improved accuracy in arithmetic may involve im- 
proved accuracy in spelling. If the ability to learn Latin is more 
closely related to the ability to learn Greek than to the ability 
to learn mathematics, then there is, other things being equal, a 
reason for putting Greek rather than mathematics with Latin in a 
common group. If attainments in arithmetic involve equal at- 
tainments in English, geography, etc., then to promote pupils 
upon their standing in arithmetic is not only a simple but also a 
just method. If motor ability is closely related to general mental 
maturity we may use it in diagnosis. 

In general our ignorance of mental relationships is enormous. 
This is due to the fact that mental relationships, like mental 
traits, are variable. The function of being a great warrior is 
really slightly related to the function of being a great poet, but 
that does not mean that every great warrior is a slightly better 

23 



24 EDUCATIONAL PSYCHOLOGY 

poet than the average man. It means that occasionally a great 
warrior is a very great poet. There is a direct relation of 39 per 
cent, between ability in Latin and ability in mathematics (the 
abilities being measured by high school marks). But this does 
not mean that every one x above the average in Latin will be 
exactly .39 x above the average in mathematics. It means that the 
average of all those who are x above the average in Latin will be 
.39a; above and that they will vary about that point. 

For instance 17 students each of whom received a mark 15 
above the average of their class in Latin might receive in mathe- 
matics the following marks respectively ( -f- standing for above and 
— for below the average): 16, 8, 5, 6, — 2, 4, 5, 6, 12, — 4, 
7, 1, 5, 6, 5, 8, 6. The average of these is 5.8, or 39 per cent, 
of 15. 

The fact of the variability of relationships has led thinkers 
to neglect their accurate measurement and either to guess at what 
relationships exist or to regard them as a matter of chance. They 
can be treated as accurately as any facts. 

It will be helpful to bear in mind the following terms: 

The status or station of any individual. 
The degree of resemblance or relationship. 
The degree of resemblance in a group. 
The degree of antagonism. 
The degree of antagonism in a group. 
The coefficient of correlation. 

The status of an individual means his position in the group in 
comparison with which we measure him. As a measure of it I 
shall use the difference between his ability and the average or 
median or modal ability of the group, calling the difference -|- 
when he is above and — when he is below the average, median or 
mode, as the case may be. Thus in a test of sixth grade girls in 
the quickness and accuracy of perception where the average ability 
was 15.7, an individual whose ability was 19 would have a status 
of -\- 3.3, one whose ability was 11 would have a status of — .4.7, 
etc. 

The degree of relationship between one trait and another in 
an individual will then be measured by the resemblance between 



THE RELATIONSHIPS BETWEEN MENTAL TRAITS 25 

his stations in the two traits, i. e., their ratio.* A minus sign 
before the ratio will mean so much antagonism or opposition of 
the two traits. The degree of resemblance between two mental 
traits in a group of individuals will be some expression of all the 
individual degrees of resemblance, — their total distribution, or 
merely their average, median or mode. When these are negative 
quantities the relationship would of course be one of antagonism. 
The following cases will illustrate these terms: 

First Ability = marking off A's on a printed page ( see page 4 ) . 

Second Ability = marking off words containing the two letters a and t on 

a printed page ( see page 9 ) . 
First Ability; Average = 15.7 and variability (A. D.)^3.65. 
Second Ability; Average =47.2 and variability (A. D.) =6.92. 

Grace Smith's stations in the two abilities were — 11.7 and 

— 2.2. Reduced to a common scale these are — y^ and 

2.20 

ggg. She thus showed a degree of resemblance of the second 

to the first ability of 

220 



692 



1170 



365 

which is .09486, roughly 9^/4 per cent. 

In the group of 48 twelve-year-old girls in the sixth grade, in 
whose cases the relationship between these two abilities was 
sought, the first ten showed the following degrees of resemblance 
(in per cents.) : 20, 42, 18, 78, —79, 214, —42, 34, —92, 446. 
The median of all the 48 individual resemblances is -|- 32 per 
cent. 

In point of fact so cumbersome and inexact a method of find- 
ing and expressing closeness of relationship is not used. I have 
described it at length to show clearly that we can measure and 
express relationships in the same way that we can mere amounts. 
The figure we shall use to express the relationship of two traits 
in a group of individuals is the coefficient of corrclaiion-, a single 

* Comparison of stations necessitates their reduction io a scale that 
means the same in both cases. This is accomplished by dividing the station 
in the one trait by the measure of the variability of that trait, and dividing 
the station in the second trait by the second trait's variability. 



26 EDUCATIONAL PSYCHOLOGY 

figure so calculated from the individual records as to give the 
degree of relationship between the two traits which will best ac- 
count for all the separate cases in the group. In other words it 
expresses the degree of relationship from which the actual cases 
might have arisen with least improbability. It has possible values 
from + 100 per cent, through to — 100 per cent. A coeflBcient 
of correlation between two abilities of -|- 100 per cent, means 
that the individual who is the best in the group in one ability will 
be the best in the other, that the worst man in the one will be 
the worst in the other, that if the individuals were ranged in order 
of excellence in the first ability and then in order of excellence in 
the second, the two rankings would be identical, that any one's sta- 
tion in the one will be identical with his station in the other 
(both being reduced to terms of the variabilities of the abilities 
as units to allow comparison). A coefficient of — 100 per cent, 
would per contra mean that the best person in the one ability 
would be the worst in the other, that any degree of superiority 
in the one would go with an equal degree of inferiority in the 
other, and vice versa. A coefficient of + 62 per cent, would mean 
that (comparison being rendered fair here as always by reduc- 
tion to the variabilities as units) any given station in the one trait 
would imply 62 hundredths of that station in the other. A coeffi- 
cient of — 62 would of course mean that any degree of superiority 
would involve 62 hundredths as much inferiority, and vice versa.* 

* Coefficients of correlation are obtained simply, though with much 
arithmetical work, by the formula 

r= ^, 

in which r:=the coefficient of correlation; 2a?.i/ = the sum of the products 
of the two stations of each individual (here the stations are taken unreduced 
to a common basis) ; ri = the number of individuals in the group; <7i = the 
mean square deviation of one ability, and (Tj the mean square deviation of the 
other. The formula is due to Professor Karl Pearson. The reader of statisti- 
cal interests is referred to the chapter on correlation in Pearson's ' Grammar of 
Science,' 2d edition, and to his numerous papers in the Transactions of the 
Royal Society. Mr. G. U. Yule has recently elaborated a formula giving a 
parallel coefficient for relationships measured by the frequency of associa- 
tion of two conditions (see Proceedings of the Royal Society, Vol. 66, pp. 
22 and 23) and Professor Pearson has given this formula an improved form. 
The reliability of any coefficient obtained by either the Pearson or the Yule 



THE RELATIONSHIPS BETWEEN MENTAL TRAITS 27 

Relationships between mental abilities or functions may be 
(1) necessary, or (2) secondarily caused. By necessary relation- 
ships are meant those cases where the mind is so organized that 
the condition of the one function always involves such and such a 
condition of the other function. If by original nature the one 
function has a certain status the other will be determined. If by 
training the status is changed the other will change so as to con- 
tinue the relation. Growth will influence both so that the rela- 
tion stays unimpaired. The second class of relationships are 
those due to the action of some cause that influences function 1 
and function 2 in similar ways. Growth and training are com- 
mon instances of such causes. 

Thus if we take all the boys in the last five years of a gram- 
mar school course the coefiicient of correlation between ability in 
perceiving the A's in a page of printed capital letters and ability 
in perceiving w^ords containing a and t in a page of print (in 
Spanish) is -|-.75. But if we eliminate in part the influence of 
differences in maturity by taking only the pupils of the limits of 
a single year, it is less, and if we eliminate still further by taking 
only those of the same year in age and of the same grade in school, 
the correlation is only -(-.53. 

Again there might be no inherent relationship between the 
ability to read and the ability to add, but if we compared well 
taught with poorly taught children we should find that the best 
adders tended to be the best readers, for the efficiency of the train- 
ing would influence adding and reading alike. 

The necessary relationships are few and small in amount. 
The relationships in general are far less close than educational 
literature would have us believe. 

formula can be readily ascertained. For a Pearson coefficient the formula 

is as follows: 

l-r" 
The mean square error of the coefficient = . == ; 

V n (1 -f-r*) 

its probable error is .0745 times the mean square error. 

In the case of the two abilities measured in the 48 twelve-year-old pirls 
in the sixth grade, the coefficient of correlation is -|- 47.7 per cent. That is 
any degree of the one ability implies in its possessor about half as much 
of the other ability. The reliability of the .477 is as follows: The chances 
are a bit over 2 to 1 that the absolutely exact relationsliip is between .376 
and .578, about 21 to 1 that it is between .275 and AM'.h 



28 EDUCATIONAL PSYCHOLOGY 

One has to hunt a long while to find any necessary relation- 
ships. It might, for instance, seem that remembering numbers 
and remembering words were alike examples of verbal memory, 
and that any degree of proficiency in one would always imply an 
equal degree of proficiency in the other. But in fact the corre- 
lation is slight and variable. To take a still more emphatic case 
the function of adding 5 7 4 and that of adding 4 5 7 seem 
necessarily related, but one may improve the time for the first 
process by practice without improving the other to an equal 
extent. Almost any, if not any, one thing in the mind may hap- 
pen in partial independence of almost any, if not of any, other 
thing. Certainly the mental traits of importance to education, 
such as efficiency in earning a living, success in school studies, 
professional skill, scientific insight of various forms and the other 
moral and intellectual virtues and vices, may appear with all sorts 
of mental accompaniments. 

It has been common in psychological and educational literature 
to presuppose that the functions which we group under the same 
name, e. g., attentiveness, somehow implied each other, that, for 
instance, a high status in attentiveness to school work was closely 
related to a high status in attentiveness to social duties, business 
pursuits, mechanical appliances and all the other facts of the 
individual's experience. Our rough and ready descriptive words, 
such as accuracy, thoroughness, reasoning power and concentration, 
have been used as if the quality must be present in approximately 
equal amount in all the different spheres of mental activity. 
The notion of any special mental act, e. g., the discrimination 
of 100 millimeters from 104, has apparently been that some gen- 
eral faculty or function, discrimination, was the main component, 
the special circumstances of that particular act being very minor 
accessories. Thus all the different acts in the case of discrimina- 
tion would be very closely related through the presence in them 
all of this same mental component. 

In fact the relationships are most noticeable by their absence 
or slight degree. The striking thing is the comparative inde- 
pendence of different mental functions even where to the abstract 
psychological thinker they have seemed nearly identical. There 
are no few elemental faculties or powers which pervade each a 



TEE RELATIONSHIPS BETWEEN MENTAL TRAITS 29 

great number of mental traits so as to relate them closely together. 

For instance the correlation in adults between (1) memory for 
figures and (2) memory for unrelated words (memory being iised 
to mean the power to keep a list in mind after once hearing it long 
enough to write it down) is only .61 (mean square error .09) ; 
the correlation in pupils of the highest grammar grade between (1) 
quickness in thinking of the opposites of words and of the letters 
preceding given letters of the alphabet and ( 2 ) quickness in think- 
ing of the sums of figures is only .30 (.05) ; the correlation in 
pupils of the same school grade and year of age between efficiency 
in perceiving capital A's and efficiency in perceiving words contain- 
ing a and t is only .51 (.02). Yet the first pair of tests would 
commonly be used indiscriminately as tests of 'memory,' the 
second pair as tests of "association' and the third pair as tests 
of 'perception/ upon the supposition that the two members of 
each pair were practically identical traits. 

A table of the known degrees of relationship will be given later. 
It will confirm the statement that the mind must be regarded not 
as a functional unit nor even as a collection of a few general 
faculties which work irrespective of particular material, but rather 
as a multitude of functions each of which is related closely to only 
a few of its fellows, to others with greater and greater degrees 
of remoteness and to many to so slight a degree as eludes meas- 
urement. 

The science of education should at once rid itself of its con- 
ception of the mind as a sort of machine, different parts of which 
sense, perceive, discriminate, imagine, remember, conceive, asso- 
ciate, reason about, desire, choose, fomi habits, attend to. Such 
a conception was adapted to the uses of writers of books on gen- 
eral method and argimients for formal discipline and barren de- 
scriptive psychologies, but such a mind nowhere exists. There 
is no power of sense discrimination to be delicate or coarse, no 
capacity for uniformly feeling accurately the physical stimuli of 
the outside world. There are only the connections between sepa- 
rate sense stimuli and our separate sensations and judgments 
thereof, some resulting in delicate judgments of difference, some 
resulting in coarse. There is no memory to hold in a uniformly 
tight or loose grip the experiences of the past. There are only 



30 EDUCATIONAL PSYCHOLOGY 

the particular connections between particular mental events and 
others, sometimes resulting in great surety of revival, sometimes 
in little. And so on througli the list. Good reasoning power is 
but a general name for a host of particular capacities and inca- 
pacities, the general average of which seems to the namer to be 
above the general average in other individuals. ^ Modern psychol- 
ogy has sloughed off the faculty psychology in its descriptions 
and analyses of mental life, but unfortunately reverts customarily 
to it when dealing with dynamic or functional relationships. 

But it is just in the questions of mental dynamics and of the 
relationships of mental traits that we need to bear in mind the 
singularity and relative independence of every mental process, the 
thoroughgoing specialization of the mind. The mind is really 
but the sum total of an individual's feelings and acts, of the con- 
nections between outside events and his responses thereto, and of 
the possibilities of having such feelings, acts and connections. It 
is only for convenience that we call one man more learned than 
another instead of giving concrete lists of the information pos- 
sessed by each and striking averages from all the particulars; 
that we call one man more rational than another instead of com- 
paring two series of rational performances. In any one field the 
comparison may give a result widely different from the general 
average. So also with activity, concentration, or any other of the 
general names for groups of mental traits. 

This view is in harmony with what we know about the struc- 
ture and mode of action of the nervous system. The nervous sys- 
tem is a multitude of connections between particular happenings 
in the sense organs and other particular events in the muscles. It 
has developed in the race as a means of fitting acts to circum- 
stances in concrete particular ways. ISTo one can imagine any cell 
action in it which should be the parallel of reasoning apart from 
some particular fact reasoned. It is structurally a collection of 
protoplasmic bonds between different parts of the body. These 
function by conducting particular impulses from one place to 
another place. There seems to be no structural arrangement by 
which the changes wrought by practice in one set of nerve cells 
could infect other cells with a similar quality. 

It follows that an individual's status in any one function need 



THE RELATIONSHIPS BETWEEN MENTAL TRAITS 31 

not be symptomatic of his status in others. We cannot infer 
arithmetical abilities as a whole from ability in addition ; nor high 
school work as a whole from work in Latin ; nor success in geog- 
raphy from success in English. We can only make such state- 
ments as : "A scholar who is marked x above or below the average 
in Latin will tend to attain a general scholarship mark of .50a; 
above or below the average." " One who is marked x above or 
below the average in English will tend to attain ASx above or 
below the average in geography." If the human mind worked in 
a simple fashion, if we could divide its actions into a few classes 
and find the efficiency of all the particular acts in any one class 
identical, we could by a few measurements estimate an individ- 
ual's make up and know what to expect of him, how to treat him, 
in what class to put him, whether or not to promote him, etc. 
The functional complexity of human mental life denies us this 
easy road to correct educational treatment. To estimate truly the 
general status of any individual is a long task requiring the sepa- 
rate estimation of his status in traits numerous and well chosen 
enough to represent all his acts and capacities. Any simple set 
of tests of mental condition is bound to be inaccurate. The ma- 
jority of those in actual use in educational practice are inadequate. 
College entrance examinations, for instance, if considered as an 
accurate measure of the mental traits necessary to secure a boy 
profit from a college course, are absurd. 

TABLE III. 
Table of Correlation Coefficients. 

E stands for efficiency, Q for quickness, A for accuracy, app. for approxi- 
mately. The first column of figures gives the number of cases studied; the 
second the coefficients of correlation. 

In the case of those tests the nature of which is not clear from the 
name used, brief descriptions are given in Appendix I. 

Tests of College Freshmen. Men. 
E Memory of figures (auditory) with .29 or .39 

E Memory of figures (visual) 14-4 (according to method 

of scoring) . 
E Memory of passage (auditory) with 

E Memory of figures (auditory) 94 .05 or .04 

E Memory of figures (auditory) with 

E Memory of length of line 91 Apparently 

E Memory of figures (visual) with 



32 



EDUCATIONAL PSYCHOLOGY 



E Memory of length of line 

E Memory of passage (auditory) with 

E Memory of length of line 

E Memory of passage (auditory) with 

Q Naming colors 

E Class Standing with Q Reaction time 

E Class Standing with Q A test 

E Class Standing with Q Association 

E Class Standing with Q Naming colors .... 
E Class Standing with E Memory of passage 

( auditory ) 

E Class Standing with 

E Memory of figures ( auditory ) 

E Class Standing with any of the other tests 



E Latin with E Memory of passage (auditoiy) 
E Mathematics with E Memory of passage 

( auditory ) 

Q Reaction time with 

E Memory of passage (auditory) 

Q Reaction time with 

E Memory of figures (auditory) 

Q Reaction time with 

E Memory of figures (visual) 

Q Reaction time with 

A Perception of pitch 

Q Reaction time with Q A test 

Q Reaction time with Q Naming colors 

Q Reaction time with Q Association 

Q Reaction time with Q Movement 



91 


Apparently 


91 


—.07 


93 


.03 


227 


—.02 


242 


—.09 


160 


.08 


112 


.02 



86 



.19 



121 .16 

No likelihood of any correla- 
tion appeared from a 
rough examination of the 
data. 
90 .22 



Q Naming colors with Q A test 

Q Naming colors with Q Movement 

A Drawing a 10-in. line with A in bisecting it 
A Drawing a 10-in. line with A in bisecting 



an angle. 



A Bisecting a line with A in 
angle 



bisecting 



an 



90 

96 

112 

104 

100 
252 
118 
153 

90 
159 

97 
123 

123 

123 



.11 

.12 

.17 

.06 

.01 
-.05 
.15 
.08 
.14 
.21 
.19 
.38 







A Dot test, 

A Perception of weight, 

A Perception of time interval, 

A Following a rhythm, 

A A test, 



with each other or with 
A drawing a line, 
A bisecting it or 
A bisecting an angle. 



All combi- 
nations 
give no 
correla- 
tion. 



Tests of Highest Grammar Grade Pupils. Boys and Girls Together. 

E Average of easy opposites, hard opposites and 

alphabet tests with E re test 160 or slight 



THE RELATIONSHIPS BETWEEN MENTAL TRAITS 33 

2. E Average of easy opposites, hard opposites and 

alphabet tests with E addition 160 .30 

3. E Average of easy opposites, hard opposites and 

alphabet tests with E misspelled word test. 160 .35 (app.) 

4. E Addition with E r-e test 160 or slight 

5. E Addition with E misspelled word test 160 .35 (app.) 

6. E r-e test with E misspelled word test 160 or slight 

7. E Easy opposites with E hard opposites 160 .28 (app.) 

8. E Easy opposites with E alphabet 160 .36 

9. E Hard opposites with E alphabet 160 .25 (app.) 

For quickness in the above tests the coefficients are (following the above 
order) or slight, 30, 10 (app.), or slight, 10 (app.), or slight, 34 
(app.), 27, 15 (app.). 

For accuracy the coefficients for 1, 6, 7, 8 and 9 are or slight, 15 (app.), 
15 (app.), 30 (app.), and 10 (app.). 

Tests of Adults. 
Relationships of mental traits in from 33 to 40 adults of very wide 
differences not only in capacity but also in training, the latter being such 
as to increase differences due to capacity and so add to adventitious corre- 
lation. All these coefficients are approximations. 



Delicacy of sense discrimination with verbal memory 

with logical " 
' with controlled thinking 

with perception 



or 
slight 



Delicacy of discrimination of length with that for weight 20 

length with that for pressure 20 

weight with that for pressure 30 

Desultory memory with logical memory 60 

Auditory memory (desultory) with visual memory (desultory) 20 

Auditory memory (logical) with visual memory (logical) 90 

Memory of forms with memory of words 50 

Memory of forms with memory of numbers 50 

Logical memory with controlled thinking 75 

Perception tests; interrelations. (A, letter combinations in English From 
words, letter combinations in Latin words, letter combinations in .20 
German words, geometrical forms, parts of speech, misspelled to 

words ) 75 

Controlled thinking tests; interrelations. Alphabet, easy opposites. From 
hard opposites, genus-species, part-whole, addition, multiplication, .20 to 

fractions, defining differences between words) 75 

Rapidity of automatic movements with rapidity of accurate controlled 

movement. Rate of reading with rate of writing 70 

Quickness in mental tests with accuracy in In general the quickest and 
mental tests. slowest are both more accurate 

than those of mediocre speed. 



34 EDUCATIONAL PSYCHOLOGY 

Exact coefficients were obtained for the following relationships: 
N = from 33 to 40. 

General efficiency in desultory memory with general efficiency in eon- 
trolled thinking with word relationships 52 

General efficiency in desultory memory with general efficiency in per- 
ception tests 59 

General efficiency in controlled thinking with word relationships with 

general efficiency in perception tests ' 41 

Perception of A's and letter combinations with perception of mis- 
spelled words and parts of speech 56 

Memory of numbers (auditory) with memory of unrelated words 

(auditory) 61 

Memory of numbers (auditory) with memory of numbers (visual)... .07 

Memory of numbers (auditory) with memory of words (visual) 30 

Tests of Children 10-15. 

Relationships of the abilities in children of the same school grade and 
same year of age and same sex. 

y r 

Memory of related words with memory of unrelated words 200 .18 

Efficiency A test with efficiency a-t test 800 .52 

(Boys 534, girls 500.) 

The relationships in the case of college freshmen are all due to Dr. 
Clark Wissler's " The Correlation of Mental and Physical Tests." Mono- 
graph Supplement to the Psychological Review, No. 16. A number of the 
others are quoted from " Correlations in the Perceptive and Associative 
Processes," by Aikins and Thorndike, Psychological Review, Vol. IX., pp. 
374-382. 

The Belationships of School Abilities. 
Educational literature is full of expressions of opinion about 
the relationships of the abilities involved in the study of the school 
subjects. For instance the ability involved in the study of one 
language is thus regarded as closely allied to the abilities involved 
in the study of other languages, less closely allied to the abilities 
involved in the study of history and still less closely to those in- 
volved in the study of mathematics and science. In colleges 
economics and history are grouped together in programs and in 
the personalities of the instructors as if they demanded the same 
mental abilities. The formal arrangement of studies in groups 
and the informal advice given to students as to their choices of 
subjects depend in part, of course, upon opinions as to the prac- 
tical usefulness of certain combinations of subjects; but in part 
also upon our opinions as to the kinships of the mental abilities 
involved. As the elective system absorbs high school programs the 



THE RELATIONSHIPS BETWEEN MENTAL TRAITS 35 

importance of making our opinions accurate increases. Besides 
this definite need of precise knowledge of the relationships be- 
tween linguistic, scientific, mathematical and other abilities, we 
may expect that the nature of these abilities themselves will be 
clearer when we have ascertained their interrelations. 

The mental traits involved in the pursuit of a school study are 
always complex and vary with the different aspects of the study 
and the different methods of teaching used. For instance phys- 
ical geography taught as a science demands different capacities 
from commercial geography taught as it commonly is. Formal 
grammar, theme writing, the history of literature and aesthetic 
appreciation may all be called 'English,' but they depend on 
capacities that have little in common. For a psychologically ade- 
quate study of the abilities involved in school work we should have 
to analyze the different studies down to elements that were in each 
case homogeneous and find the relations amongst them. Such a 
study would, I may add, at once show what a variety of differ- 
ent mental operations go by the name arithmetic or by the name 
grammar. 

The more immediately pressing question and one more easily 
answered neglects the heterogeneous nature of a school subject and 
asks simply : " Taking the subjects as they stand, how are the 
abilities they severally require related ? How far does a person's 
station in one subject determine his station in any other?" 

Dr. Clark Wissler* measured the relationships between the 
abilities in several of the college studies as taught to undergradu- 
ates at Columbia University, using as measures the regular marks. 
His results are as follows. The figures in parentheses give the 
number of cases studied : 

Latin. Rhetoric. Germnn. 

Mathematics 58 (228) .51 (222) .52 (115) 

Rhetoric 55 (223) 

French 60 ( 130) .30 ( 122) 

German Gl (120) ' .61 (132) 

Greek 75 (121) 

Mr. W. P. Burrisjf again using the tx?achers' marks as the 
measure of ability, found the following relationships for high 

• ' The Correlation of ^lental and Physical Tests.' 

t Columbia Contributions to Education, Vol. XI., No. 2, p. 26 [132]. 



36 



EDUCATIONAL PSYCHOLOGY 



school subjects, as taught in 19 representative high schools, using 
nearly 1,000 individuals. 

English. Latin. Mathematics. History. Geometry. 

Latin 48 

Mathematics 39 .40 

History 40 .43 .33 

Science 41 .44 .41 .40 

Algebra .45 

Mr. S. C. Parker, in a study* of the marks of 245 first year 
high school students, all from the same year's class of the same 
school, found the relationships, the abilities being measured by 
the teachers' marks, to be those given in table IV. 

TABLE IV. 



English , 
History . 

Science. . 

Algebra 

Drawing 

German. 

French . 

Latin ... 



xi 


>. 


V 


<£ 


Ciij 


d 


si 


m 


M 


t> 






d 




"5) 

R 


O 
tn 


a 

.2 
u 

CO 


< 




a 




(U 




.62 


.58 


.55 


.15 


.65 


.49 


.62 




.56 


.38 


.10 


.49 


.58 


245 














.022 














.58 


.56 




.40 


.33 


.62 


.48 


212 
.026 


212 
.031 












.55 


.38 


.40 




.20 


.52 


.68 


243 


243 


211 










.025 


.034 


.036 










.15 


.10 


.33 


.20 




.06 


.30 


243 


243 


211 


242 








.042 


.042 


.039 


.041 








.65 


.49 


.62 


.52 


.06 




.33 


109 


109 


84 


109 


109 






.031 


.044 


.038 


.042 


.064 






.49 


.58 


.48 


.68 


.30 


.33 




75 
.053 


75 
.044 


75 
.054 


74 
.035 


74 
.068 


29 
.096 




.62 


.43 


.54 


.54 


.01 


.38 




58 
.046 


58 
.066 


25 
.085 


58 
.055 


58 
.088 


33 
.094 




.585 


.51 


.53 


.511 


.164 


.498 


.512 



C3 



.62 
.43 



.54 

.54 
.01 
.38 



.502 



Upper figure = coefficient of correlation. 
Middle " =no. of cases. 

0.6745(1 — r2) 



Lower 



= P.E.oir-- 



/« (1 + 7-2) 

That is, the chances are 1 to 1 that the coefficient obtained from an infinite 
number of cases would not differ from the upper figure by more than the lower 
figure. 

* As yet unpublished. 



TEE RELATIONSHIPS BETWEEN MENTAL TRAITS 



37 



AVEBAGE OF InTEERELATIONS OF FOLLOWING SUBJECTS. 



English. 


.59 


Latin. 


.43 


Latin. 


.53 


English. 


.42 


History. 


.49 


Science. 


.41 


Science. 


.46 


History. 


.39 


Mathematics. 


.46 


Mathematics. 


.38 



Brinckerhoff, Morris and Thorndike,* using the regents' 
marks given to students all taught in the same high school, found 



the following coefficients ; 





Latin. 


English. 


Mathematics. 


Science. 


History. 


German. 


Latin 














English 


.50 .07 












Mathematics 


.31 .10 


.09 .09 










Science 


.35 .13 


.26 .09 


.07 .11 








History 


.44 .09 


.41 .07 


.26 .08 


.61 .07 






German 


.48 .11 


.30 .10 


.48 .08 


.57 .09 


.42 .10 




Drawing .... 


.40 .10 


.20 .10 


.02 .11 


.30 .10 


.16 .10 





Boys. 


Girls. 


Averag 


.36 


.43 


.395 


.49 


.38 


.435 


.17 


.14 


.155 


.42 


.30 


.36 


.16 


.12 


.14 


.14 


.11 


.125 



Mr. A. G. Smith, f using teachers' marks as the measure of 
ability, found the following relationship for grammar school sub- 
jects as taught in the ISTew York City schools during the last four 
years of the school course. The correlation coefficients were cal- 
culated from the marks in English, Mathematics, Geography and 
Drawing of 739 boys and 786 girls. 

English and Mathematics 

" " Geography 

" " Drawing 

Mathematics and Geography 

" " Drawing 

Geography and Drawing 

Correlation coefficients between arithmetic and geography were 
also calculated from objective tests in the two subjects given to 
80 boys and 80 girls in the fourth grade. The results were : 

BoyR. Girls. 

Grade A .23 Grade A .28 

Grade B .43 Grade B .57 

Together .33 Together .43 

For our purpose the most striking thing about these figures is 

their small amount. It is safe to say that in a grammar or high 
* Columbia Contributions to Ediicatioii, Veil. XI., No. 2, p. 30 [13G]. 
■\ Ibid., pp. 13 and 14 [119-120]. 



38 EDUCATIONAL PSYCHOLOGY 

school student a deviation from the average ability in any one 
subject implies by and large a deviation in any other not more 
than half as great. The most talented scholar in one field will 
be less than half as talented in any other. The most hopeless 
scholar in one field will in another be not so very far below 
mediocrity. The discovery of the exact amount of these rela- 
tionships thus disposes finally of the opinion that brightness is 
brightness and that those who possess it may use it equally well 
in any field, and reemphasizes the existence of special aptitudes 
for special school studies. It also emphasizes the folly of using 
any one study as a basis of grading or promoting, and the special 
folly of so using arithmetic. English is obviously better. 

Another impressive characteristic of the figures is the closer 
correlation of abilities in boys than in girls in the grammar grades. 
Its explanation is difiicult. It may be a real difference of mental 
organization. If so it would show that males have for ages been 
more rigidly selected for intellectual capacity than have females. 
It may be due to the existence in boys of a stronger ambition to 
reach such and such a grade in all subjects. It may be due to 
more accurate grading by the four teachers who marked the boys 
than by the four teachers who marked the girls. 

Finally the figures show clearly that the different school sub- 
jects have different degrees of kinship. We might say that geog- 
raphy was a sister to English and drawing only a cousin. To 
make such comparisons in much detail, however, we need correla- 
tion coefficients obtained from a wider range of subjects and by 
more accurate methods. The kinships, so far as measured in these 
first studies in the field, do not agree at all well with those pro- 
claimed by educational writers. Science, for instance, is here 
closer to Latin than to mathematics and closer to English than 
is history. Algebra and geometry are hardly more closely re- 
lated than mathematical and non-mathematical subjects. From 
the incomplete study of regents' examination marks and direct 
tests, I am convinced that the common talk about the affinities of 
the school subjects is largely guesswork. 

A few pages back attention was called to the diverse capacities 
required by a single school subject. As proof and illustration of 
the statement there made I will quote from a study made by Mr. 



THE RELATIONSHIPS BETWEEN MENTAL TRAITS 39 

W. A. Fox and myself* of the relationships amongst the abilities 
involved in addition, multiplication, easy fractions, harder frac- 
tions and problems. For high school girls the coefficients were as 
follows : 

1. Addition with Multiplication 75 .05 

2. Addition with Fractions 2 44 .12 

3. Addition with Fractions 1 19 .19 

4. Addition and Multiplication combined with Fractions 1 and 2 

combined 46 .09 

5. Addition and Multiplication combined with Problems A and 

B combined 55 .08 

6. Fractions 1 and 2 combined with Problems A and B combined. . . .44 .12 

7. Addition and Multiplication combined with Fractions 1 and 2 

and Problems A and B, all four combined 54 .08 

8. Fractions 1 with Fractions 2 20 .17 

9. Fractions 1 with Rational Computation 58 .10 

10. Fractions 2 with Rational Computation 57 .09 

The figure in the second column gives a measure of the unreliability of the 
coefficient due to the small number of cases studied. Thus the first line 
should read, "A relationship of 75 per cent., and the chances are 2 to 1 that if 
an infinite number of cases had been studied the coefficient then found 
would not vary from .75 by more than .05, would be, that is, between .70 
and .80." 

Ability in arithmetic is thus but an abstract name for a num- 
ber of partially independent abilities. Courses of study in that 
subject should therefore allow for special capacities for its differ- 
ent phases ; and wise teachers will bear in mind that they are teach- 
ing not arithmetic to good and bad arithmeticians, but addition, 
subtraction, multiplication, fractions, problems — computation, 
manipulation and applied arithmetic — to children whose capaci- 
ties for these several lines of work are in each case a separate 
problem. It should be noted also in Burris's table that the coeffi- 
cient for algebra and geometry is not much higher than that for 
a mathematical with a non-mathematical subject. 

The facts given in this chapter should not only prove the gen- 
eral propositions (1) that knowledge of mental relations is pro- 
ductive of insight into mental life and educational work, and (2) 
that the mind is a host of highly particularized and independent 
abilities; they should also demonstrate the opportunity, need 
and utility of researches in this field. In every section of mental 
life, in every section of school work, there is an easy chance to 
measure mental relationships. 

* Columbia University Contributions to Education, Vol. XT., pp. 138-143. 



CHAPTEE V. 

ORIGINAL AND ACQUIRED TRAITS, 

What a human being becomes in life depends upon what is 
born in him and what happens to him. What is born in him 
again depends upon the constitution of the germ and ovum which 
were his first beginning and upon what happened to the ovum 
after fertilization, but before birth. We have no common word 
to designate characteristics due to the constitution of the fertilized 
ovum which is a human life at its outset. ^Let us call them origi- 
nal qualities or traits or capacities. The words antenatal and 
postnatal have been used to distinguish the influences which alter 
man's nature before birth from those acting thereafter. Since 
we shall be little concerned with the antenatal acquisitions, I shall 
use the words environment, nurture, experience or acquisitions to 
refer to the events after birth. 

^ A human being is then the sum of an original nature acted on 
by antenatal influences and the later environment. 

The first problem of educational science concerns the relative 
shares of these agencies in determining human thought and con- 
duct. Are there perhaps mental traits which a given environment 
can produce in any living animal, be it a protozoon or a mammal, 
a butterfly or a man ? Are there, at all events, mental traits which 
the environment can produce with equal facility in any one of the 
thousands of children who will enter a city's schools this fall? 
Are there differences in original nature which will make the same 
environment produce from one a biologist and from another a 
chemist? In general how far does original nature prepare for a 
man's career ; how far, on the other hand, is it an indifferent cul- 
ture medium for the circumstances of life ? 

This must not be confused with another question, that of how 
far original nature limits absolutely an individual's total mental 
growth. Original nature might make the same environment pro- 
duce from one a biologist and from another a chemist and still not 
prevent two different environments from making the first a chem- 

40 



ORIGINAL AND ACQUIRED TRAITS 41 

ist and the second a biologist or leaving both wild savages. The 
environment may alvt^ays work to increase or diminish original 
differences, though how far it may do so is a question. But that 
environment can alter original natures and mask their intrinsic 
qualities gives no reason to deny the existence of these qualities. 
Their existence, their extent and their degree of specialization 
can be discovered only by a comparison of individuals subjected 
to the same environment. 

One special aspect of the general problem of the extent and 
degree of specialization of original nature that appears worthy of 
note in human affairs is the question of how far in human beings 
particular talents are original. Is a man from the beginning 
organized to be a novelist or only to be a writer of fiction or only to 
be an artist of some sort or perhaps even only to be a man of abil- 
ity ? It is a plausible statement that our inner natures are organ- 
ized only in rough outlines, that the currents of mental activity 
are fi:sed in their general direction but left to take what particular 
channels circumstances may decide. But this or any opposite 
statement must be put in exact terms of how much, how far, in 
what cases, to be theoretically satisfying or practically useful. 
The facts needed to settle these questions could be obtained and 
measured, though not easily. But they have not been. 

If we could submit a sufficient number of children to identical 
environmental training in some particular, the individual differ- 
ences which they manifested in spite of the identity in training 
would serve as a partial measure of the action of original nature 
plus antenatal acquisitions.* If we could be sure that on the par- 

* Antenatal conditions are evidently indirectly influential upon our mental 
make-up. A mental as well as a physical life may be brought to a sudden 
end by disease or deformity appearing in utero. It may by similar fate be 
permanently burdened. The burden may even bear more heavily upon the 
nervous system, and so upon mental faculty, than upon the other bodily organs. 
And there might well be a direct influence through the mother's blood which 
would infect the child with her mental qualities so far as such were due to 
enzj'mes or toxins in her blood. There might even be some mysterious bonds 
by which her mental life might, aside from this known cluinnel of influence, 
form the child into her likeness. The last case seems higlily improbable and 
the preceding probability is only a matter of conjecture. Nothing is known 
with quantitative precision concerning the influence of antenatal conditions 
upon mental traits. 



42 EDUCATIONAL PSYCHOLOGY 

ticular trait in question antenatal influences acted alike in all the 
cases, we should have a partial measure of the contribution of orig- 
inal nature alone. The action of original nature would then be to 
produce the amount of the trait by which the extremes of the in- 
dividuals differed plus an unknown constant. The action of dif- 
ferences of original nature, which is the really important fact, 
would be to produce all the differences found. Experiments ap- 
proximating to this ideal type could be made in orphan asylums 
where the environment was uniform for all. None have yet been 
made. If we could find children identical in original nature and 
antenatal influence and observe the results where the environment 
for some differed from that working upon others, we could have a 
partial measure of the amount of influence of the environment and 
a complete measure of the difference in action of differences in the 
environment, which again is the really important fact. Such data 
might be furnished by a study of identical twins, and a rough at- 
tempt at such a study has been made by Francis Gal ton.* Un- 
fortunately no one has as yet repeated it. 

One might try to argue from the differences found amongst 
people in general by choosing cases where the environmental ac- 
tion could be allowed for or by correlating amounts of difference 
in the environmental action with amounts of difference in the 
mental traits, but the problem thus attacked becomes very intri- 
cate. Fairly exact evidence proving that original nature is an 
active force in determining a man's thoughts and acts, though not 
measuring its amount, will appear when we consider the facts of 
family resemblance. These facts will also answer in part the 
question as to the specialization of original nature, for it must be 
at least as specialized as is inheritance. 

From Galton's article, as the best and indeed the only quan- 
titative study of the potency of original nature, I shall quote 
at some length. Galton studied twins who were closely similar 
in infancy but whose environments differed and twins who were 
in infancy notably unlike but whose environments were in all 
essential features identical. The persistence of similarities in 

* " History of Twins," in " Inquiries into Human Faculty," London, 1883; 
reprinted in the Teachers College Record, Vol. II., No. 3. The former volume 
is out of print and is rare. 



ORIGINAL AND ACQUIRED TRAIT8 43 

the former case and of differences in the latter gives a measure 
of the influence of original nature. 

This evidence in the first case consists of illustrations of iden- 
tical mental habits, tastes, associations of ideas and suscepti- 
bilities to mental diseases. The cases of unlikeness seem to 
him to be due to such alterations in the* amount of energy as 
could be caused by illness or lowered nutrition rather than to 
fundamental qualities of mind. 

The evidence in the case of the twenty pairs in the second 
group shows no exceptions to the rule that no weakening of 
inborn differences by similarities of nurture is observable. The 
following are representative parental observations : 

1. One parent says: " They have had exactly the same nurture from their 
birth up to the present time; they are both perfectly healthy and strong, 
yet they are otherwise as dissimilar as two boys could be, physically, men- 
tally, and in their emotional nature." 

2. " I can answer most decidedly that the tmns have been perfectly 
dissimilar in character, habits, and likeness from the moment of their birth 
to the present time, though they were nursed by the same woman, went to 
school together, and were never separated till the age of fifteen." 

3. "They have never been separated, never the least diflFerently treated 
in food, clothing, or education; both teethed at the same time, both had 
measles, whooping-cough, and scarlatina at the same time, and neither had 
any other serious illness. Both are and have been exceedingly healthy and 
have good abilities, yet they differ as much from each other in mental cast 
as any of my family differ from another." 

4. "Very dissimilar in body and mind; the one is quite retiring and 
slow but sure; good-tempered, but disposed to be sulky when provoked;— the 
other is quick, vivacious, forward, acquiring easily and forgetting soon ; quick- 
tempered and choleric, but quickly forgetting and forgi%'ing. They have been 
educated together and never separated." 

5. " They were never alike either in body or mind and their dissimilarity 
increases daily. The external influences have been identical; they have never 
been separated." 

6. " The two sisters are very different in ability and disposition. The 
one is retiring but firm and determined ; she has no taste for music or draw- 
ing. The other is of an active, excitable temperament; she displays an 
unusual amount of quickness and talent, and is passionately fond of music 
and drawing. From infancy, they have been rarely separated even at school, 
and as children visiting their friends, they always went together.' 

7. "They have been treated exactly alike; both were brought up by 
hand; they have been under the same nurse and governess from their birth, 
and they are very fond of each other. Their increasing dissimilarity must 
be ascribed to a natural difference of mind and character, as there has been 
nothing in their treatment to account for it." 



44 EDUCATIONAL PSYCHOLOGY 

8. "They are as different as possible. (A minute and unsparing analysis 
of the characters of the two twins is given by their father, most instructive 
to read, but impossible to publish without the certainty of wounding the 
feelings of one of the twins, if these pages should chance to fall under his 
eyes.) They were brought up entirely by hand, that is, on cow's milk, and 
treated by one nurse in precisely the same manner." 

9. " The home-training and influence were precisely the same, and there- 
fore I consider the dissimilarity to be accounted for almost entirely by 
innate disposition and by causes over which we have no control." 

10. " This case is, I should think, somewhat remarkable for dissimilarity 
in physique as well as for strong contrast in character. They have been un- 
like in body and mind throughout their lives. Both were reared in a country 
house, and both were at the same schools till aet. 16." 

The two lines of evidence taken together justify, in Galton's 
opinion, the following general statements : 

" We may, therefore, broadly conclude that the only circumstance, within 
the range of those by which persons of similar conditions of life are affected,, 
that is capable of producing a marked effect on the character of adults, is 
illness or some accident that causes physical infirmity. . . .' The impression 
that all this leaves on the mind is one of some wonder whether nurture can 
do anything at all, beyond giving instruction and professional training. There 
is no escape from the conclusion that nature prevails enormously over nurture 
when the differences of nurture do not exceed what is commonly to be found 
among persons of the same rank of society and in the same country." 

Some measurements of the perceptive and associative powers 
of pairs of twins which I have been able to make seem to show 
that the preeminence of inborn nature which Galton finds in 
the fundamental traits of character does not hold good of more 
specialized habits and capacities. My measurements are not as 
yet adequate for a full conclusion; but it is extremely unlikely 
that they will show correlations between identical twins of more 
than .70. 

The importance to educational theory of a recognition of the 
fact of original nature and of exact knowledge of its relative 
share in determining life's progress is obvious. It is wasteful 
to attempt to create and folly to pretend to create capacities and 
interests which are assured or denied to an individual before he 
is born. The environment acts for the most part not as a cre- 
ative force but as a stimulating and selective force. We can 
so arrange the circumstances of nurture as to reduce many un- 
desirable activities by giving them little occasion for appearance, 
and to increase the desirable ones by ensuring them an adequate 



ORIGINAL AND ACQUIRED TRAITS 45 

stimulus. We can, by the results we artificially attach to wis- 
dom, energy or sympathy, select them for continuance in individ- 
ual lives. But the results of our endeavors will forever be limited 
as a whole by the slow progress of change in the original nature 
of the race, and in different individuals by inborn talents and 
defects. 

Thinkers about the organized educational work of church, 
library and school need especially to remember three facts. 

First. — For the more primitive and fundamental traits in hu- 
man nature such as energy, capability, persistence, leadership, 
^sympathy and nobility the whole world affords the stimulus, a 
stimulus that is present well-nigh everywhere. If a man's origi- 
nal nature will not respond to the need of these qualities and the 
rewards always ready for them it is vain to expect much from 
the paltry exercises of the school room. 

Second. — The channels in which human energy shall proceed, 
the specific intellectual and moral activities that shall profit by 
human capacities, are less determined by inborn traits. The 
schools should invest in profitable enterprises the capital nature 
provides. We can not create intellect, but we can prevent such a 
lamentable waste of it as was caused by scholasticism. We can 
not double the fund of human sympathy, but we can keep it 
clear of sentimental charity. 

Third. — The important moral traits seem to be matters of 
the direction of capacities and the creation of desires and aver- 
^ sions by environment to a much greater extent than are the 

important qualities of intellect and efficiency. Over them then 
education has greater sway, though school education because of 
the peculiar narrowness of the life of the school room has so 
far done little for any save the semi-intellectual virtues. 

The one thing that educational theorists of to-day seem to 
place as the foremost duty of the schools — the development of 
powers and capacities — is the one thing that the schools or any 
other educational forces can do least. 

It is from time to time complained that a doctrine which re- 
fers mental traits largely to original make-up, and consequently to 
ancestry, discourages the ambitions of the well-intentioned and 
relieves the world's failures from merited cnntonipt. But every 



46 EDUCATIONAL PSYCHOLOGY 

one is agreed that a man's free will works only within limits, and 
it will not much matter for our practical attitude whether those 
limits are somewhat contracted. If the question is between orig- 
inal nature and the circumstances of nurture it is rather more 
encouraging to believe that success will depend on inherent quali- 
ties than to refer it entirely to advantages possessed during life, 
and contempt is merited more by him who has failed through 
being the inferior person than by the one who has failed simply 
from bad luck. Whether or not it is merited in either of the 
two cases we shall decide in view of our general notions about merit 
and blame, not of our psychological theories of the causes of con- 
duct. . 



CHAPTER VI. 

THE INHERITANCE OF MENTAL TRAITS. 

1^0 intelligent person can doubt that our original natures are 
not a mere matter of chance but are in part determined by the 
ancestry from which we spring. If the original nature of a dog 
could by a miracle be given a human birthright and nurture, it 
would still grow into the body and mind of a dog. And as we 
have human rather than canine minds because our original natures 
are the offspring of human beings, so also, we should probably 
agree, we have the Anglo-Saxon type of minds partly because 
we spring from Anglo-Saxon ancestry rather than from Aus- 
tralian bushmen. Some of us would feel sure that the original 
natures of a hundred sons of feeble-minded or insane parents 
would differ from the original natures of a hundred sons of healthy- 
minded men and women, though in both cases the race — i. e., 
the remote ancestry — might be the same. 

With sufficient knowledge we could analyze any man's original 
mental nature into elements due (1) to his being descended from 
animals rather than plants, (2) to his more immediate descent 
from vertebrates rather than invertebrates, (3) to his still more 
immediate descent from mammals rather than reptiles or birds, 
and (4) from primates rather than rodents, carnivors, etc., 
and so on with the contributions due to ancestry of the human 
species, of the European stocks, of the Anglo-Saxon breed, of such 
and such great-grandparents, grandparents and parents. There 
would be little dispute about the importance of these elements save 
in the case of the more immediate ancestry. Here we find the 
widest range of opinion. This is the more to be regretted because 
all the social sciences and especially education need as a starting 
point precise knowledge of the differences in original mental 
make-up within the human species and of their relationship to 

immediate ancestry, 

47 



48 EDUCATIONAL PSYCHOLOGY 

Our somewhat extensive study of the facts bearing upon this 
topic will include the following topics. 

1. Methods of measuring similarities of related individuals. 

2. Proof that immediate ancestry is a true cause of physical traits. 

3. Evidence that the same holds true in at least some mental traits. 

4. A review of the measurements of mental inheritance. 

5. The general characteristics of mental inheritance. 

6. The transmission of acquired mental traits. 

A preliminary caution is necessary. To say that a man's 
original nature depends upon his ancestry does not mean that it 
is an exact facsimile of any one or any combination of his ances- 
tors. There is no reason to believe that four sons of the same 
parents and consequently of the same total ancestry will have 
the same original natures. Indeed we know they will not, save 
by chance, for twins who have presumably in some cases identical 
or nearly identical antenatal influences and nurture may vary 
widely in both physical and mental traits. What ancestry does 
is to reduce the variability of the offspring and determine the 
point about which they do vary. 

Take for instance the capacity to form intelligent habits or 
associations amongst sense impressions, ideas and acts. The num- 
ber of associations between situation and act, the number 
that is, of things an animal can do in response to the multitude 
of conditions of life, varies tremendously throughout the animal 
kingdom. The free swimming protozoa studied by Professor 
Jennings had in addition to the common physiological functions 
hardly more than a single habit. The sum of the life of Para- 
moecium is to eat, breathe, digest, form tissues, excrete, reproduce, 
move along in a steady way, and when passing from certain media 
into others to stop, back, turn to the aboral side and move along 
again as before. At the other extreme is a cultivated human being 
whose toilet, table manners, games, speech, reading, business, etc., 
involve tens if not hundreds of thousands of associative habits. 

If now we take a thousand descendants of human beings and 
count up the number of associative habits displayed by each we 
shall of course find a great variability. Some of our thousand 
human offspring will learn fewer things than some dogs and 
cats. Some of them may learn many more than any of the 



THE INHERITANCE OF MENTAL TRAITS 49 

parents from whom tliey sprang. . But on the whole the offspring 
of human beings will vary about the human average instead of 
about the general animal average, and the average deviation of the 
human group will be far less than that of the whole animal 
kingdom. 

To illustrate again, the children of parents who are, say, 3 
inches above the mean of the general population in stature will vary 
not about that general mean but about a point 2 inches above it ; 
and whereas the variability of the general population is 1.7 inches 
(probable error), the variability of children of the same parents 
is only 1.0 inches (probable error).* 

Immediate ancestry will then, when influential, cause children 
to deviate from the general average toward the condition of their 
parents and to vary less among themselves than would the same 
number of unrelated individuals. 

The measurement of the resemblances between brother and 
brother, parent and child, uncle and nephew, etc., involves pre- 
cisely the same statistical problem as the measurement of the 
relationships between mental traits. The difference is that here 
we measure the resemblance between the stations of two indi- 
viduals in the same trait, whereas in Chapter IV. we measured 
the resemblance between the stations of the same individual in 
two traits. Here the correlation is between individuals, there 
between mental traits themselves. A Pearson coefficient here 
measures the general tendency of brother to be like brother or 
father to be like son in efficiency in the same mental trait, whereas 
there it measured the general tendency of one mental trait to be 
like another in efficiency in the same group of individuals. 
A correlation of 1.00 between brother and brother in mathe- 
matical ability would mean that the brothers of a set of men 
who were -f- a in that ability would themselves be -|- a, and 
similarly of course for the brothers of men ranlcing — a in that 
ability. .52 correlation M^ould mean that the brothers of men 
-j- a and — a will be on the average 52 per cent, of -f~ ^^ and of 
— a respectively. If we turn the discussion from " the relation- 
ship of two traits in the same series of individuals " to " the 

* This illustration is based »i)on the data for stature in Galton's " Nat- 
ural Inheritance." 



50 EDUCATIONAL PSYCHOLOGY 

relationship of a series of pairs of individuals in the same mental 
trait," the account of correlation in Chapter IV. will fit per- 
fectly our present purpose. 

In some cases hereditary resemblance will be expressed in 
the less adequate form of a higher probability of a certain con- 
dition in those related to individuals of that condition than in 
people taken at random. This form of expression will be used 
of the inlieritance of deafness and of insanity in families. Exact 
measures of the reduction of variability due to inheritance are 
possible by a simple comparison of the variability of the selected 
class ' children of such and such ' with that of the total popula- 
tion. 

To avoid the confusion of similarities due to similar home 
training with those due to similarity in ancestry we should 
properly measure resemblance in pairs in cases where the train- 
ing of any one pair is the same as that of any other. This could 
be done exactly with mental traits in related animals and approxi- 
mately with brothers and sisters brought up from birth or soon 
after in asylums. In default of such studies we must choose 
cases where the environment has little or no influence of a sort to 
beget family resemblances or get some means of making a proper 
discount for such influence. 

Before describing the similarities of closely related individuals 
in mental traits I shall present the results of studies in the case 
of some physical traits which will prove that heredity is a vera 
causa, since in them the causation of the similarities found bv 
similar training is out of the question. 

The coefficient of correlation between brothers in the color of 
the eyes is 52 per cent. (.5169), But parents could not, if they 
would, exert any environmental influence upon the color of their 
children's eyes. The fraternal resemblance must be due to the 
resemblance in ancestry. 

In height we find the coefficient of correlation between father 
and son to be .3, between brother and brother to be .5, in other 
words a son on the average deviates from the general trend of the 
population by .3 the amount of his father's deviation, a brother 
by .5 the amount of his brother's, etc. ISTow no one can imagine 
that tall fathers try especially to make their sons tall. ISTor will 



THE INHERITANCE OF MENTAL TRAITS 51 

the class ' men two inches above the average height ' feed their chil- 
dren any more than men one inch above it. 

The coefficient of fraternal correlation in the case of the 
cephalic index (ratio of width to length of head) is .49 (.4861). 
Here it is utterly incredible that fathers do anything to their 
children that would tend to produce in them similar indices. 

Finally take color of hair. Fraternal correlation is .5452. 
Here again home influence could not cause one whit of the re- 
semblance. 

Immediate ancestry can and does, apart from any other force, 
cause in whole or in part the abmodality of an individual in the 
case of stature, cephalic index and eye color. There is no reason 
to suppose that the brain is less influenced by it than the tissues 
that cause height, or the shape of the skull bones that causes 
cephalic index, or the deposits of pigment that cause eye color. 
Immediate ancestry is thus a probable cause for original mental 
nature. And when we are in doubt as to a choice between it and 
the environment as the cause of differences in mental traits of 
individuals at any age, we must not forget that the influence of 
the latter is after all largely a matter of speculation, w^hile the 
influence of ancestry is in physical traits a demonstrated fact. 

The Influence of Ancestry on Mental Traits. 
1. Deafness. 

Deafness may be considered a physical trait because it is due 
to physical causes, but so are all mental traits. The real differ- 
ence is that we know more about the causes in the one case than in 
the others. The manifestation and results of deafness are cer- 
tainly mental traits. 

The brother or sister of a person born deaf is found to be deaf 
in 245 cases out of 1,000, almost one case out of four. We do 
not know exactly the number of deaf amongst 1,000 brothers and 
sisters of hearing individuals, but it is certainly less than 1, 
probably much less. That is, a person of the same ancestry as a 
congenitally deaf person is at least 245 times (probably many 
more) as likely to be deaf as a person of the same ancestry as a 
hearing person. The child of two parents both of whom were 



52 EDUCATIONAL PSYCHOLOGY 

born deaf is at least 259 times * as likely (probably many more) 
to be deaf as tbe child of two hearing parents. In this case, as 
with the physical traits described, there is no reason to impute any 
efficacy to training. Parents born deaf would take pains to 
prevent deafness in their children. 

2. Ability to learn to spell. 

Mr. E. L. Earle measured the spelling abilities of some 1,000 
children in the St. Xavier school in New York by careful tests. 
As the children in this school commonly enter at a very early 
age, and as the staff and methods of teaching remain very con- 
stant, we have in the case of the 180 pairs of brothers and sisters 
included in the 1,000 children closely similar school training. 
Mr. Earle measured the ability of any individual by his deviation 
from the average for his grade and sex and found the coefficient of 
correlation between children of the same family to be 51 per 
cent. That is, any individual is on the average 51 per cent, as 
much above or below the average for his age and sex as his brother 

or sister. 

Similarities in home training might theoretically account for 
this, but any one experienced in teaching will hesitate to attribute 
much efficacy to such similarities. Bad spellers remain bad 
spellers though their teachers change. Moreover, Dr. J. M. Rice 
in his exhaustive study of spelling ability f found no relationship 
between good spelling and any one of the popular methods, nor 
between poor spelling and foreign parentage. Yet the training of 
a home where the parents do not read or spell the languages well 
must be a home of relatively poor training for spelling. 

These facts together with those given by Galton prove the ex- 
istence of mental inheritance. Our questions concerning it are, 
therefore, vital questions and it becomes our duty to review the 
measurements of the resemblances of related individuals that 
have been made. 

Measurements of Mental Inheritance. 

The first serious study of the inheritance of mental traits was 

made in the 60's by Erancis Galton and reported in ' Hereditary 

* Percentagea of deaf children, 25.931. E. A. Fay, ' Marriage of the Deaf 
in America,' p. 49. 

t See Chapter VII. for a fuller account of his method and conclusions. 



TEE IXEERITANCE OF MENTAL TRAITS 53 

Genius ' in 1869. He examined carefully the careers of the 
relatives of 977 men each of whom would rank as one man in 
four thousand for eminent intellectual gifts. They had relatives 
of that degree of eminence as follows: fathers 89, brothers 114, 
sons 129, all three together 332 ; grandfathers 52, grandsons 37, 
uncles 53, nephews 61, all four together 203. The probable 
numbers of relatives of that degree of eminence for 977 average 
men are as follows : fathers, brothers, and sons together 1 ; grand- 
fathers, grandsons, uncles and nephews all together 3. Galton 
argues that the training due to the possession of eminent relatives 
can not have been the cause of this superior chance of eminence in 
the relatives of gifted literary men and artists. 

To recapitulate: I have endeavored to show in respect to literary and 
artistic eminence — 

1. That men who are gifted with high abilities — even men of class E — 
easily rise through all the obstacles caused by inferiority of social rank. 

2. Countries where there are fewer hindrances than in England, to a 
poor man rising in life, produce a much larger proportion of persons of cul- 
ture, but not of what I call eminent men. [England and America are taken 
as illustrations.] 

3. Men who are largely aided by social advantages are unable to achieve 
eminence, unless they are endowed with high natural gifts. 

Galton demonstrates that the adopted sons of popes do not 
approach equality in eminence with the real sons of gifted men. 
He so orders his studies of men eminent in other fields as to leave 
very slight basis for one who argues that training and opportunity 
rather than birth caused the eminence attained. Finally Gal- 
ton's own opinion, that of an eminently fair scientific man based 
upon an extensive study of individual biographies, may safely be 
taken with a very slight discount. He says : " I feel convinced 
that no man can achieve a very high reputation without being 
gifted with very high abilities." 

The historic importance of Galton's ' Hereditary Genius,' 
the originality and ingenuity of its author and its substantial 
results should make his book the first to be read by every student 
of mental inheritance. 

In 1889 Galton published his ' ISTatural Inheritance,' the re- 
sults of more precise studies * of resemblances amongst related 

* These studies were reported in various memoirs from 1871 to 1887. 



5.4 EDUCATIONAL PSYCHOLOGY 

individuals in stature, eye color, the artistic faculty and diseases. 
He found the resemblance between parents and their children 
in the mental trait studied (artistic faculty) to be a little greater 
than in the case of stature. The essential facts from which this 
inference is drawn are that in 30 families where both parents 
were artistic 64 per cent, of the children were so, whereas in 150 
families where neither parent was artistic only 21 per cent, of the 
children were so (page 218), ]^o attempt is made to divide the 
causation of this resemblance between birth and training. 

Professor Karl Pearson, who after Galton is the creator of 
precise knowledge of hereditary resemblances, has recently 
widened his studies so as to include mental traits. His investi- 
gation of mental resemblances between brothers reported to the 
Koyal Society late in 1901 {Nature, Vol. 65, p. 118) is per- 
haps the most valuable research in educational psychology yet 
made. 

From 800 to 1,000 pairs of brothers were measured by their 
teachers with respect to the following traits : intelligence, vivacity, 
conscientiousness, popularity, temper, self-consciousness, shyness. 
In intelligence the measure was a grade from one to six according 
to ability; in temper from one to three. In the other traits the 
individual was put into an upper or a lower class. The co- 
efficients of fraternal correlation were found to be: 

Intelligence 4559 

Vivacity 4702 

Conscientiousness 5929 

Popularity 5044 

Temper 5068 

Self-consciousness 5915 

Shyness 5281 

The average of all is 5214 



'&■- 



The nature of all but the first of these traits at once suggests 
that home environment rather than original nature is the cause 
of the similarities found. So also does the fact that the resem- 
blance is slightest in the first trait. But such a conclusion would 
be rash. Professor Pearson finds the fraternal correlations of 
these same individuals in hair color and cephalic index to be 
.5452 and .4861 (averaging .515T) ; and of another large set of 
brothers in stature, forearm length, span of arms and eye color 



THE INHERITANCE OF MENTAL TRAITS 55 

to be respectively .5107, .4912, .5494 and .5169 (averaging 
.5171). The resemblances in these physical traits can not be 
due at all to the fact that brothers have the same home environ- 
ment, yet the resemblances here are as great as in mental traits. 
So argues Professor Pearson, and we must I think agree to prefer 
a real to a conjectured cause. To believe that the fraternal re- 
semblances in mental traits are due to environmental influences 
which work to such an extent as exactly to counterfeit in amount 
the force of inheritance, is hardly possible to a critical mind. To 
believe that the influence of inheritance in causing these resem- 
blances was supplemented by the influence of environment also 
requires us to postulate the improbability that the two forces 
together should in mental traits exactly equal the force of 
inheritance in the case of physical traits. Galton has suggested 
that home training may appear much more efficacious than it is 
because children by birth resemble their parents and so readily 
follow their guidance and example, while other people's children 
might be but little susceptible to the same influences. 

A second criticism of Professor Pearson's conclusion might 
be that the teachers who reported cases of brothers tended to select 
brothers whose likeness was notable and to grade them alike oftener 
than the facts warranted. It is true that if you seek information 
from people without special training in the field of science con- 
cerned, the answers obtained are well-nigh sure to be compounds 
of fact and prejudice, but there is apparently no reason to believe 
that teachers have any prejudicial belief in fraternal similarity. 
If in any way in the questions asked the suggestion was made 
that Professor Pearson was interested in resemblances, this second 
criticism becomes a serious one. 

A third criticism is that teachers' measures of the traits in 
question are very inaccurate. This is a fact, but a fact which 
in no wise lessens the proof of fraternal resemblance, as a little 
thought will make .clear. It would only lessen the precision of 
the results. 

Tests of 62 brother-brother and sister-sister pairs of school 
children 10-14 years old with the opposites test (see appendix) 
gave a correlation of .20; tests upon 113 similar pairs with the 
A test gave a correlation of .34; and tests with 107 similar pairs 



56 EDUCATIONAL PSYCHOLOGY 

with the a-t test gave a correlation of .27. Using as a measure the 
ability shown in the last two tests together, the correlation was .34.* 
In all these cases the coefficients are too low, in the opposites test 
much too low. For the children, representing the school popula- 
tion of the five highest grades of the grammar school, included an 
unfairly large proportion of bright relatives and dull relatives of 
mediocre children. 

In the course of this same study any children rat^d by their 
teachers as exceptionally bright or exceptionally dull were so 
recorded. I find that of the 38 children who were the brothers 
and sisters of the exceptionally bright children 6 were excep- 
tionally bright and none were exceptionally dull, while of the 
36 children who were the brothers and sisters of the exceptionally 
dull children 2 were exceptionally dull and none exceptionally 
bright. 

I have also calculated the resemblance in the case of 86 pairs 
of siblings (i. e., children of the same parents) tested for delicacy 
of discrimination of length. I do not regard the material as 
very reliable, but it is clear that there is real resemblance and 
that it is above .30 in amount. 

Burris f found the resemblance in high school marks to be 
as follows: 

English 24 550 

Latin 24 400 

Mathematics 20 554 

History 16 450 

Science 21 350 

General Scholarship 22 554 

These coefficients, like my own, are subject to a constant error, 
due to the fact that a high school population is itself a selected 
group of more than average ability in academic studies. This 
error probably makes his coefficients lower than they should 
really be. 

In rate of movement, regardless of the accuracy of the result, 

* The reliabilities of these figures are, so far as the number of cases is 
concerned, such that the chances are even that the true coefficients will not. 
vary from them by more than .08, .05, .06 and .05 respectively. 

f Columbia Contributions to Education,' Vol. XI., No. 2, p. 22 (128). 



THE INHERITANCE OF MENTAL TRAITS 57 

Miss ISrorsworthy * found no resemblance amongst siblings (171 
pairs). 

General Characteristics. 

The only known causes of original nature are ancestral con- 
tributions and the normal tendency to vary. If one chooses to 
believe that chance or miracle assists to make the germs and ova 
of animals and men what they are, it will be very difficult to 
demonstrate to him that he is in error, but a wise psychology will 
prefer to use the habitual hypothesis of biology. 

Several important questions arise. The chief question is 
concerning the ancestral contributions. Do they include the re- 
sults of the ancestors' acquisitions ? Does the child inherit the 
results of his parents' mental improvement or degeneration during 
life or is his resemblance to them limited to what they were 
months before they were born ? Is his original nature the result 
of their total make-up or only of their original natures ? The 
answer to this question will in part decide what improvement of 
the race we can expect from education and also what particular 
prophecy we can make concerning the original nature of any indi- 
vidual. The evidence bearing upon this now historic quarrel will 
be presented in a separate section. 

A second question concerns the way in which the several 
ancestors' contributions combine to form the offspring's nature. 
The mental conditions of a father and mother might in the case 
of any trait blend, tending to produce in the offspring a condition 
half way between their own; or one might contribute certain 
of his traits in their entirety and the other certain of hers ; or the 
combination of one trait in one and another trait in another 
might produce in the offspring a third trait radically different 
from either. In briefer terms inheritance might be blended, al- 
ternate or creative. A in one parent plus B in the other might 
tend to produce V2(^ H~ -^)j either A or B, or a new thing C. 

In human height, for instance, inheritance is blended; in the 
coloration of animals it is often alternate ; in the case of the 
combination of two species it is i")erhaps creative. In human 
mental traits blended inheritance seems far the most common, 

* In an unprinted report. 



58 EDUCATIONAL PSYCHOLOGY 

but it is conceivable that, for instance, the children of a superior 
mathematician and a good speller might be (1) fairly good 
in both mathematics and spelling or (2) good in either mathe- 
matics or spelling or (3) mediocre in mathematics and spelling 
but good or bad in linguistic work. 

The term prepotency, used in discussions of heredity, should 
not be confused with alternate inheritance. The former means 
a tendency of some trait in some individual to appear in more of 
his offspring than chance would warrant in alternate or blended 
inheritance. ISTor should extreme cases of blended inheritance, 
cases where the normal variability in the proportion of the two 
parents' shares reaches a maximum, be confused with alternate 
inheritance. Blended and alternate inheritance can be distin- 
guished by the distribution of the amounts of resemblances. 

In the former the amounts of resemblance of children to 
their two parents taken separately will give a normal distribu- 
tion; in the latter they will give a distribution compounded 
equally of two normal distributions. In the former the amounts 
of resemblance of siblings will give a normal distribution ; in 
the latter they will give a distribution compounded of a species 
of positive resemblance (due to those cases where the two sib- 
lings take after the same parent) and of a species of resem- 
blance or rather lack of it due to the cases where they take after 
different parents. The mode of the latter will be zero unless 
resemblance in the trait in question acts as one cause of marriage. 

Nothing is known about the frequency of prepotency in 
mental traits. 

A third question concerns the relative contributions of an- 
cestors of different degrees of remoteness. Take for instance the 
original nature of the individual x whose ancestry is shown in 

the diagram. 

GH IJ KL MN 

V V V V 
C D E F 

\/ \/ 

A B 



What are the respective shares of A and B, of C, D, E, F, 
etc., in determining his make-up? There is as yet no exact 
evidence upon this point in the case of mental traits. 



THE INHERITANCE OF MENTAL TRAITS 59 

We do know however that the nearer the ancestor the more 
he contributes, but we do not know just how much more. In 
the case of physical traits the case is apparently different accord- 
ing as inheritance is blended or alternate. For stature the law 
formulated by Galton is that the influence of the parents is twice 
that of the grandparents, and that again twice that of the great- 
grandparents, etc. For the coat color of Bassett hounds Karl 
Pearson * finds the different generations back of the parents to 
be much more equal in potency than this, the chances being that 
the percentages taking after each ancestral generation will be as 
follows : 

Per cent, taking after ( 1 ) parents 63.256 

(2) grandparents 3.488 

(3) great-grandparents 3.105 

. (4) 2.764 

(5) 2.460 

(6) 2.190 

Other questions concern the range, amount and degree of 
specialization of mental inheritance. The data summarized on 
pages 51 to 57 are too limited to allow any sure statement of 
the range of mental life over which heredity has influence, or 
of its general strength. Some mental traits may be little or not 
at all connected with inheritable qualities. Presumably the in- 
fluence of heredity will be most marked in traits important for 
survival and in those that are fundamental in mental life. 

In two cases the facts provide us with a means of measuring 
the specialization of mental inheritance. Burris gives the fra- 
ternal resemblance in general scholarship as well as in the separate 
studies. It is but little greater in the former case (.22 as com- 
pared with an average of .21 for the five separate coefficients). It 
would seem therefore that either the inheritance was specialized 
for each trait or that the same single trait caused excellence in all 
studies. But the inter-correlations amongst the studies show the 
latter alternative to be false. On the other hand the fraternal 
resemblance in the ability measured by the two different tests of 
perception taken together was greater than the average of the 
resemblances found in the two abilities taken separately (.34 vs. 
.305). 

Proceedings of the Royal Society of London, Vol. 66, pp. 140-164. 



* 



60 EDUCATIONAL PSYCHOLOGY 

Galton, who had this problem clearly in mind, notes a num- 
ber of relevant facts, some of which I quote. Concerning the 
judges of England between 1660 and 1865 he says: 

Do the judges often have sons who succeed in the same career, where 
success would have been impossible if they had not been gifted with the special 
qualities of their fathers? . . . 

Out of the 286 judges, more than one in every nine of them have been 
either father, son or brother to another judge, and the other high legal rela- 
tionships have been even more numerous. There cannot, then, remain a 
'doubt but that the peculiar type of ability that is necessary to a judge is 
often transmitted by descent. ('Hereditary Genius,' pp. 61 and 62.) 

Concerning the eminent relatives of eminent statesmen he 

says : 

Thirdly, the statesman's type of ability is largely transmitted or in- 
herited. It would be tedious to count the instances in favour. Those to the 
contrary are Disraeli, Sir P. Francis (who was hardly a statesman, but rather 
a bitter controversialist) and Horner. In all the other 35 or 36 cases in my 
appendix, one or more statesmen will be found among their eminent relations. 
In other words, the combination of high intellectual gifts, tact in dealing with 
men, power of expression in debate, and ability to endure exceedingly hard 
work, is hereditary. (Ibid., pp. 103 and 104.) 

Similar specialization of inheritance is shown to be the case 
with the relatives of great commanders, literary men, poets and 
divines. With men of science the fact is much more pronounced, 
twenty-two out of the twenty-six eminent sons of eminent scien- 
tific men having been eminent in science. This extreme special- 
ization of resemblance is in part due, Galton thinks, to training. 

Mendelssohn and Meyerbeer are the only musicians in my list whose 
eminent kinsmen have achieved their success in other careers than that of 
music. (Ibid., p. 231.) 

The eminent relatives of eminent painters seem to be well- 
nigh universally gifted in the same special line. In Galton's 
list all the relatives mentioned are painters save four. These 
were gifted in sculpture (2), music (1) and embroidery (1). 

Of course there is in the case of all of Galton's facts the 
possibility that home surroundings decided the special direction 
which genius took, that really original nature is organized only 
along broad lines. Moreover, it is difficult to see just what in the 
nervous system could correspond to a specialized original capacity, 
say to be a judge. Still the latter matter is a question of fact. 



THE INHERITANCE OF MENTAL TRAITS 61 

and of the former issue Galton's studies make him the best judge. 
We should note also that it is precisely in the traits the least 
amenable to environmental influence, such as musical ability, that 
the specialization of family resemblance is most marked. 

Our last question is about the physical basis of mental inherit- 
ance. The basis of all the facts of hereditary resemblance is of 
course the relations not of an adult to adult relatives but of the 
germs of the one to the germs of the others. All these facts will 
find their final explanation only in a full account of the influences 
that act upon the germ plasm and the relation between parental 
germ plasms and the germs produced thereby. Such a full ac- 
count is not at hand and even such relevant facts as are known 
are often incomprehensible by any save technical students of 
biology. We can, however, hold ourselves in a position to get clear 
views by never forgetting that children are the direct offspring, not 
of parents, but of the germs of those parents. The qualities of the 
germs of a man are what we should know in order to prophesy 
directly the traits of his children. One quality these germs surely 
possess. They are variable. Discarding syntax and elegance for 
emphasis, we may say that the germs of a six-foot man include 
some six-feet germs, some six-feet-one germs, some six-feet-two, 
some five-feet-eleven, some five-feet-ten, etc. Each human being 
gives to the future, not himself, but a variable group of germs. 
This hypothesis of the variability of the germs explains the fact 
that short parents may have tall sons, gifted parents stupid sons, 
the same parents different sons. If now we could measure 
the similarity amongst the germs of the same parent we should 
have a basis for the similarity amongst related individuals. The 
amount of difference amongst brothers, for instance, is due to the 
variability in the germs ; the amount of similarity to the correlation 
in the germs. In one of his most brilliant applications of sta- 
tistical method Karl Pearson has shown that the correlation be- 
tween germs from the same ancestor is probably numerically equal 
to the correlation found in fraternities. The germs may be ex- 
pected to be in this respect like other undifferentiated like organs 
and from many samples of such Pearson has calculated coefficients 
of correlation. 



62 EDUCATIONAL PSYCHOLOGY 

The Transmission of Acquired Mental Traits. 

Whether we are by nature* what our parents were by nature 
alone or what they were by nature plus training may be argued 
from two points of view. The probability of the latter event may 
be estimated from our knowledge of the physical relations be- 
tween parents and offspring or its actual occurrence may be deter- 
mined from evidence. It is beyond the purpose of this book to 
present even a summary of such arguments pro and con. Indeed, 
except for the need of a statement limited to the inheritance of 
acquired mental traits, it would be unwise to add a new chapter 
to the voluminous discussions already in print. 

Some matters seem fairly sure. 

1. Whatever changes occur in the nature of the chromatic 
substance in the nuclei of the germs and ova of the parents will 
influence the original nature of the offspring, for the nuclei of the 
germ and ovum ai^e the original nature of the offspring. And 
nothing else will. 

2. The germs and ova are made directly from the germ 
plasm (ovaries and testes) of the parents, not from their bodies 
in general. Just as the bone marrow makes blood, or the cells 
of the neural tube the nervous system, so the germ plasm makes 
the germs and ova. 

3. The cells which are specialized to form the germ plasm, 
that is to do the work of producing the next generation, are set 
off and begin their more or less separate careers long before 
the individual is born. 

4. The line of inheritance is thus from germs to germ plasm 
to germs to germ plasm and so on. 

5. The germ plasm is connected with and related to other 
structures in the body, including those of the central nervous 
system, in no more intimate way than are the other structures 
amongst themselves. The nervous system influences the growing 
germ or ovum as it may influence the cells of the liver or heart 
or skin. 

* It will be observed that antenatal influences from the mother are ex- 
eluded, from the discussion. A mother may, for instance, acquire some dis- 
eases and transmit them through the blood, but she transmits them by 
infecting the growing child, not by altering the quality of its original nature. 



THE INHERITANCE OF MENTAL TRAITS 63 

6. 1^0 known mechanism exists by whicli such alterations of 
the nervous structure or of the quality of the nervous tissue as 
would correspond to changes in human mental traits, might pro- 
duce in the germs changes fitted themselves to become in the adult 
form similar structures or qualities to those which caused them.* 

7. The acquisition of specific mental traits by an individual 
seems thus unlikely to modify his germs so as to reproduce the 
trait acquired. With very general traits such as mental vigor 
or weakness, health or degeneracy, the case might well be different. 
Such general mental traits might be correlated with bodily con- 
ditions which would include the germ plasm as well as any other 
parts of the body. The correlation, however, is by no means per- 
fect. As to precise measures of how far acquired conditions of 
general health involve changes in the germ plasm and of how 
far such changes influence mental qualities in the offspring, there 
are none. 

The obvious way to settle our question is not by contemplating 
these inferences from present knowledge of the process of devel- 
opment, but rather by making the crucial experiment of letting 
animals acquire some mental traits and observing the nature 
of the offspring. No such experiments of a decisive nature 
have been made. If for generation after generation mice were 
offered palatable food always in the shape of yellow cubes 
smelling of grease and unpalatable food always in the shape 
of white balls smelling of cheese, were kept in a cage so arranged 
that on going into a certain alley they always received an electric 
shock, and were otherwise given a chance to learn certain habits, an 
observer could measure for generation after generation the quick- 
ness of formation of these habits and detect the slighest improve- 
ment. Ten or twenty generations would thus give a final answer 
to an ancient quarrel. 

* It should however be said that Professor Jacques Loeb has suggested 
(Monist, Vol. VII., pp. 481-493) that in some cases of instinctive mental traits 
the organic basis may be the presence of some chemical substance, and that in 
these cases the change during life in the nature or amount of such substance 
might directly affect the germs so as to perpetuate the acquisition. This 
possibility is, so far as human mental traits are concerned, wholly a matter 
of speculation. 



64 EDUCATIONAL PSYCHOLOGY 

The popular idea of evidence on the question is as follows: 
"Jones studied mathematics and became a gi'eat mathematician. 
So was his son. His father's studies must have helped to make 
him so." The retort is of course easy: "Why was Jones I^o. 
1 a great mathematician ? Because of his original nature. Why 
was Jones 'No. 2 ? Because his father's original nature made 
him so." We shall never get on with this question by begging it. 
The mere fact of family similarity never need imply the inherit- 
ance of parental acquisitions. 

A more advanced type of argument adduces the growth of 
some mental trait in the species as a whole. For instance it is 
said : " How explain the growth of language save by supposing 
that the constant exercise of the mind in this respect has resulted 
in ever-increasing facility in offspring until the few shouts and 
mutterings and wails of primitive man have become the compli- 
cated speech of to-day." 

The retort is as easy as before : " Language has grown be- 
cause on the whole those with the most inborn capacity for it lived 
and begot their like while those with the least inborn capacity died 
and left few or no heirs to their linguistic poverty." ISTot the 
inheritance of acquisitions but the selection of those who could 
acquire ! 

The field of animal instincts has been well canvassed by 
biologists in search of light upon our general question. The gist 
of their discoveries is: (1) that many instincts are certainly not 
the result of a summation of acquisitions, e. g., those that appear 
only once in a lifetime. (2) Most instincts are generalized rather 
than specific, though most acquired habits are specific rather than 
generalized. But a specific habit inherited should give a specific 
instinct. Thus instead of a number of fears of special enemies 
such as cats, hawks, skunks, etc., chicks have a general alarm 
at strange and impressive objects. (3) Useless instincts are very 
slow in being lost unless selection is at work.* Thus chicks 
swim, though not 1 in 1,000 of their ancestors has done so for 
thousands of years. 

* If acquisitions became inherited of course unused habits would tend 
to disappear, would, we might say, be disinherited. 



THE INHERITAIs'CE OF MENTAL TRAITS 65 

It is remarkable that certain evidence from human psychol- 
ogy has failed to receive attention in all these long debates. 
Human life offers a favored case for transmission of an acquired 
trait where transmission has clearly failed. The congenitally 
blind from eye defects do not have visual images of the sun, stars 
or any other of the permanent objects of the natural world, yet 
their ancestors for at least hundreds of generations, save in the 
cases of those lacking in visual images, had such images again 
and again. If the hourly experiences of hundreds of ancestral 
generations do not become a part of inborn equipment, we could 
hardly expect anything to do so. 

The burden of evidence is thus against the transmission of 
acquired traits. Adequate experiments may conceivably reverse 
some of the conclusions based on existing evidence, but for the 
present we must deny the mental acquisitions of one generation 
any considerable share in the original natures of the next. Orig- 
inal nature springs from original nature. Its improvement de- 
pends on the elimination of the worse, not on their reformation. 
It depends on nothing else, unless there be an inherent tendency 
in human germs to vary in a definite direction, and that a good 
one. We educate the original nature of the race only by fostering 
its good elements and encouraging their fertility and by debarring 
the worse elements from reproduction or by eliminating them 
outright. 

There is a peculiar superstitiousness and prudishness in pres- 
ent-day life which recoils from thinking of death as a benefactor 
or of fertility as a duty and a crime. A college president can 
get hundreds of thousands of dollars to teach men various accom- 
plishments, but he would be laughed at if he asked for $10,000 
to prevent the most gifted young man in the college from remain- 
ing childless until 35. Either from ignorance or from timidity the 
writers on both education and sociology never add to their perpet- 
ual exhortations to petty improvements of social conditions a 
reference to the summum honum, improvement of that which 
must be the sole preserver of the good that is and the creator of 
the better that may be — the original nature of the race. 



J 



CHAPTER VII. 

THE INFLUENCE OF THE ENVIRONMENT. 



The Amount of Influence. 

The questions suggested by the title of this chapter include 
all those of the mental and moral education of individuals. It 
would be silly presumption to pretend to answer them all. Pre- 
cise quantitative answers, to which this book is restricted, can be 
given to none of them. 

Theoretically there is no impossibility. Once we have esti- 
mated the original nature of a man or group of men, we have 
simply to note the mental changes consequent upon this or that 
change in climate, food, school-training, friendship, sermon, occu- 
pation, etc. Practically the complexity of the action of physical 
and human influences upon intellect and character hampers scien- 
tific study and favors guesswork. The environment includes a 
practical infinitude of different causes; these act differently upon 
different types of original nature and at different ages and with 
different cooperating circumstances; in many cases their action 
is very complex and must be observed over long intervals of 
time. Indeed it has been common to deny even the possibility 
of a science of the dynamics of human nature and to remain 
content with the haphazard opinions of novelists, proverb makers 
and village wise men. 

Moreover it is only by the utmost ingenuity and watchfulness 
that studies of changes in human nature can be freed from a char- 
acteristic fallacy — that of attributing to training facts which are. 
really due to original nature or to selection. For instance, col- 
lege graduates are found to have a much greater likelihood of 
being elected to Congress than have non-graduates. Therefore it is 
said that a college education causes to some extent political success. 
But it is clear that even before they went to college the group of 
youth who did go were different from those who did not. Their 
later election to Congress may as well have been due to the mental . 
traits which they possessed by birth or otherwise and which caused 

66 



TEE INFLUENCE OF THE ENVIRONMENT 67 

their inclusion in the class 'boys who go to college' as to any 
changes produced in them by the college training itself. In other 
words, that they were the class selected by the college is as im-^ 
portant a fact as that they were the class trained by it. 

Again it is said : " Who can doubt the enormous disciplinary 
value of the study of Latin and Greek when we see the admirable 
intellects of the men so trained in the English universities ? " 
But of course in England being born from the class whose chil- 
dren go to the university of itself ensures to an individual uncom- 
mon mental ability. 

To avoid this confusion of causes which train with those which 
select is extremely hard. Any class of individuals whom we 
study because they have been subjected to a certain training is 
almost sure to be a class not only trained by but also selected by 
that training. Suppose that we wish to study the influence of 
a high-school course, or that of the classical as opposed to the 
scientific course, or that of training in independent research, or 
that of immoral surroundings. High school graduates are but 
8 per cent, of grammar school graduates ; and no one would 
claim that they represent an entirely random picking therefrom. 
They are surely selected for better birth, better abilities and 
better ideals. Again, in most high schools the graduate of the 
classical course represents not only a different training but also a 
different selection, commonly a superior selection. So also scien- 
tific men are a class resulting not only from the training given by 
research work but also from the selection of those eager to do 
and fitted to do that work. Children brought up in a morally 
bad environment are almost sure to be of morally inferior ances- 
try. The ordinary arrangement of social and educational careers 
rarely presents us with convenient cases of similar nature, some 
with, some without, the form of training we are studying. 

The difficulty of eliminating the influence of selection is no ex- 
cuse for its neglect. Yet one may hunt through thousands of pages 
of discussions of the influence of certain studies, school svstems, 
schemes of culture, religious beliefs, etc., without finding a hint of 
its recognition. 

Either because of the general complexity of environmental in- 
fluences upon any mental trait and the mixture of selective 



<68 EDUCATIONAL PSYCHOLOGY 

w^ith formative influences or because of the infrequency of scien- 
tific habits and ideals in students of education, there are few 
facts of sufficient security and precision to be quoted.* Only 
rarely has educational science progressed beyond the reasoned 
opinions of more or less capable judges. We have our beliefs 
about the causal relations between a hot climate and indolence, 
necessity and invention, lack of parental control and crime, re- 
ligious training and morality, etc., but we can not be said to know 
these influences with adequate surety or to have any knowledge 
whatever of their precise amount. 

One general statement may be added concerning the amount 
of influence of the environment. Since the factor of selection 
is commonly neglected the influence of the environment is com- 
monly over-estimated; in the judgment of the present writer 
very much so. 

In place of any general summary of conflicting and inse- 
cure opinions I shall quote at some length from the studies 
by Dr. J. M. Kice of the influence of various environmental fac- 
tors upon efficiency in spelling and in arithmetic. Although their 
author does not take advantage of some important statistical 
methods, these studies represent in a general way the type of 
investigation which should be made in every field. 

Dr. Rice tested the spelling ability of some 33,000 children 
in twenty-one schools representing a great variety in spirit, 
methods, time given to spelling and in other respects, f He then 
compared the conditions in schools where the pupils did well in 
spelling with those in schools where they did badly. He notes 
first of all the slight differences between schools, only 6 out of 
the 21 schools being outside the limits 73.3 and 77. 9, and the 
decrease in variation amongst schools as we pass from lower to 
higher grades (see table V), facts which show that the differences 
in spirit or method that characterize schools can not make much 
difference in achievement. Of school systems where mechanical 
methods are in use as compared with more progressive systems 
he says: 

* In the literature of sociology and economics there may be studies quali- 
fied by their statistical adequacy and freedom from the fallacy of selection 
to serve as models. If so they are not readily discovered. 

-^ Forum, April and June, 1897. 



THE INFLUENCE OF THE ENVIRONMENT 



69 



Indeed, in both the mechanical and the progressive schools the results 
were variable; so that while, in some instances, the higher figures were 
secured by the former, in others they were obtained by the latter; and the 
same is true of the lower figures. For example, School B, No. 11, in which 
the best average (79.4) was obtained, belongs to a very progressive system; 
while School A, No. 12, which made only 73.9, belongs to one of our most 
mechanical systems. And it is a peculiar incident that, in both these cities, 
the results in the only other school examined are exactly reversed, although 
the environment is about the same. 

He eliminates the possibility that home reading or cultured 

parents or English rather than foreign parentage is the cause of 

the differences amongst schools by making the comparisons of 

table VI. 

TABLE VI. (No. 3 of the original account). 





03 


09 


n 


6 

5lO 


O (U 




^^ a ti 








Grade. 


3 

c 


en 

3 
o 


P. 

3 

Pui 

o 


OS <o 


ildren 
oreign 
rentag 


u 

> 


t Child 
ng For 
Iguage 
Home. 


0) 


Idren 
Qskille 
iborers 


Oj 

> 




6 


d 

izj 


6 
!2; 


a) 




< 


No. o 

Heari 

Lar 


< 




< 


H f Fourth .. 


4 


27 


821 


64.7 


155 


65.2 


159 


64.9 


129 


62.5 




Fifth.... 


4 


29 


829 


76. 


153 


77.4 


157 


76.7 


129 


74.5 


W w J 


Sixth 


4 


22 


778 


69.7 


185 


69.6 


165 


70.3 


119 


70.4 


55H 


Seventh. 


4 


18 


566 


78.8 


81 


82.5 


52 


81.5 


55 


76.8 


m 


l Eighth .. 


4 


19 


528 


83.1 


72 


83.2 


64 


83.2 


76 


85. 



Dr. Rice further tabulated the results in accordance with the 
methods of instruction used in the different schools, interviewing 
some two hundred teachers for that purpose. He does not give 
the detailed results, but assures us that there is no reason to be- 
lieve that there is any clear choice between oral and written spell- 
ing, writing isolated words and writing sentences, the sight or 
flash method and its absence. Phonic reading does not make bad 
spellers, nor do written language work and wide general reading 
make good spellers. " In brief," says he, " there is no direct 
relation between naethod and results. . . . The results varied as 
much under the same as they did under different methods of in- 
struction." 

That the amount of time given is not the cause of success in 
teaching spelling is shown by the facts of table V. Schools 
giving 15 or 20 minutes daily to spelling do as well as those 
giving 40 or 50. 



70 



EDUCATIONAL PSYCHOLOGY 



•[ooqos 



<mo<mo<p^<:j'<K'< 





•M\o 


1—1 


rHi-ll>.I>.t-05 0i05 


o o 

T-l r-t 


t-H 
I-H 




•JS31-30U3JU3S 

'■Aviooqos 


T-l 


75 
77.6 

75.2 

77.9 

76.6 

77.7 
77.9 


76.2 






03 

5 


•ilirea sajnniH 


1 


lOOOiOIOiCI 1 1 1 1 1 1 

|iMcoMcolec.-il 1 1 1 1 1 1 


IS 1 1 


1 <=> 

1 •* 




•JS3X 

-noijisodcaoo 


1 


CO -^ ^ COTti 
loioiloioioJoil 1 1 1 1 1 1 


99.2 
99.1 


1 1 




•jsai-aonajnag 


1 


rH 00 Oi C<) t^ 

M CO lO Tti 1 «>.■ CO 1 1 1 1 1 1 1 1 

xoooooo'oooo' ' ' ' ' ' ' 


83.5 

82.5 


CO 
00 




01 

> 

si 

I> 


•i£lTBaB8jnniw 




lOO lOOiO lO lO |0 lO 

|-<}<eo l-^MrH leo l»o Ico |(M 


IS 1 1 


30 
ool year 


CO 


•1B3X 

-nojiisodmoo 


1 


98.7 
99.4 

98.7 
99.2 

99.4 
99.2 


99.2 
98.6 


f of sch 


W 

IX! 


•}sax-80n3?n9S 


CO' 


78 
73.1 

77.2 
81.1 

85.6 

86.5 

84.7 

80 

79.5 


76 
sond hal 


TABLE V. 

AGES FOR INDIVIDUA 


ja 
to 


•iliBa sainuiK: 


a 


lOOOOiOOiCiC liOiCiOOiO 


1 i IS 


25 
lall A se 


•JB3X 

-nonisodtnoo 


1 


ootr^occo ooi-t i^-* 

1 00 00 l>^ OO' 1 1 I-' OJ 1 1 00 00 1 1 


99.2 


f, and sn 


•js3x-9on3in3g 




1 t^ -H -^ CO 1-H o CO c4 eo' ic co' oJ 

' t- t^ CO l> t^ 00 ' ' CO t- t- l> t- t^ 


72.7 


63.4 

65.8 

first hall 


fa 
> 


u 
03 
0) 

s: 


•X[isa: eajtiniH 




|lOC0(Mr-IC0T}<|r-ll 1 \ ^ \ 1 


1 1 IS 


idicatea 




•1B3X 

-uoijiBodmoo 


I 


■* "^i 00 eo coco CO 05 
It-^oor-Iool It-^ool |t^i>^| 1 


98.6 
98.9 


mall B ii 




•}S3X-30U9}U8g 


CO 

ai 


CD00CO-* r-J eO 0000 (N 

(M'l-icooiio^ 1 >-5oo-^'cooco 

' t- 00 t^ t^ t- 00 ' ' «> t^ t^ t^ t^ 00 


02 

CO (N rfi CO 

1 1 coi>:oo 




1 

S3 


•^Il-ea samuiK 


1 


liOTj^co-^lc^lcol-^ll \ -^ 


1 1 1 lo 

1 1 1 CO 


1 lO 
1 (M 




•!|sax 
-uoniBOdnioo 


1 


00 !>• Oi lO Oi lO •* r-( 00 
1 CO CO lO I>^ t^ !>•■ t-' t -■ 1 1 CO" CO 1 1 


96.6 
98.3 


1 1 




•iS8X-30U8;U8S 


CO 

CO 


00 CO lO 00 oo CO -* -^ ■^ 
IrHi-Ht^cd-^io 1 lococdodcocd 

l<Ot^l>-cOCOi>. ' 'l>.cOcOCOCOCO 


•* 05(M CO 

1 1 rH lO >-H CO 
1 1 CO t^ CO CO 

pq <) fq <^ pq <! 




•looqos 


-< 


mo<JWo<!p;o 


<1 M 


< 






•^110 


iH 


i-li-(l>I>.l>.0J05 0> 


o o 

I— 1 <— 1 


f— 1 

I— ( 



TEE INFLUENCE OF THE ENVIRONMENT 



71 





•looqos 


fq-ilpqfqQHa-<M<lM 


•^ilD 


1— l(MC<JU5iOutiiCCDC00503 


'■Av looqog 


79.4 
73.9 
79.0 
73.4 
78.8 
77.3 
77.9 
72.0 
72.7 
73.8 
73.3 


SI 


•^n^a sainuiK 


l§ 1 1 1^ 1 1 IS 1^ 1^ r r i 1 1 1 


nS3X 

-uouisodtnoo 


|oi| 1 1 loicji] 1 |oi| 1 oj.oi 00 05 1 1 1 1 


•jsax-9on3}U9s 


t--C0O3C0eOO5C<)(MiXi -"tiOSTti OJMC^ICO 00 
00 00 05 05 05 00 00 00 00 00 00 00 00 00 00 00 00 00 00 


5 


•iliBQ sainniK 


lOI 1 |(N1 1 |0|0|iC|0I01 1 lo 


'5S9X 
-noijisodraoo 


00 cot-- i> (Nooior; 
00 odco 00 ododoooi 

050505 05 05050505 


00 !>eot- eo-«tii-Hooeoeo lO 

00 t> OSl-OOt-OO OOOO t-t^t-t^l>-OD<X>00 


»4 

g 

XI 


•^li-Ba eajnuiH 


leolll lllcviliMlcolcqlr-ilcolco 


•1S9X 

-aoi;isodnioo 


od| 1 1 1 |j>^od| |odoo| |i>^odoo't-^| | | | 

05 0505 0505 05050505 


•isax-9on3jn9S 


t^ I— 1 Ttl ifl CO t^ 00 to 00 (N 05 t^ 00 CO "5 

Tfi icioeoo6i>..-Hodc^s4o50550^od odiMi-Ioi 
t- t^ t^ t^ t^ lO «> <0 t^ t^ «0 ^ t^ CO to to t^ to to 




■^IiBd sajnaiH 


|>0| lOOOl 1 |0|0|iO|U3|0|0| 1 


•isax 
-noniBodoioo 


05 vc oo-<*< ooeo ic to lo c^ 
t-^o6| 1 i |tc>i>;| |t-^o6| |o6o6o6a)| | 

0505 0505 0505 05O5O505 


•!}B3X-30n31U9S 


to 00 ■* •^ Tj* to to -^ -"tl C<1 rH to Tfl to •<*' 00 to IM 

Tf 1-4 to' CO ■^' 05 CO CO ^' CO -^ 05 to oJ cc' to ~ -^ to to' co od 
t^ootoc^t^t^t^t^oooot^t^t^c^t^t^t^t^tot^t^i^- 


03 
ID 

S3 


■iinBaeainutH 


IIOI 1 1001 1 |0|i0|0|0|0|0|0 

Icol 1 It-hI I Iim1t-iIc<)I(mIc<)I(nI-<i< 


■■jsax 
-noijiBOduioo 


96.3 
97.9 

97 
96.6 

97.4 
97.9 

97.9 


■lB3x-3on9jn9s 


TfO0<Mi-ieO<M COIMOOIMi— (tOM-* 00 T}<-^ 

tdo5co'co'coi>^ 1 1 |Tj5tDOt^a5'c<ioiodiOi-< It^od 

t^ t- lO to iC to ' ' ' t^ to l~ to to to lO to to to ' lO to 


•looqog 


pq-5imM«Wt[^<^M<^pq 




■-ilD 


.— I <M 01 lO lO lO lO to to C5 05 



"9 

to 
J 

s 

o 



Hi 

o 

O 

W 
< 

a 

O 



o 

Em 
W 
O 



72 



EDUCATIONAL PSYCHOLOGY 



1-5 







1 


g g 


g 


g g g 


g 


g 


g 


g g g g g g 


g 


g gl 










•ua3[Bi naiiM. 1 


-«i <i5 ^ -si Ph PM Pk -^ f^' <i PM P< <i Ph Ph" -< fM PM 1 












1 


+ 








■XTiBfT sainmw 1 


cooio io>ooo o :o : oooococ^ido 












1 


ic «o (M-^^ «5«oo .CD . Ti< CO ec '* '^ l> "* 












•siojig: 


l>=D!:^rHlCrHTj<«DC5lO(Mlft>0<M(Mt^T-l<r' 


1—1 






. 


^BOiaBqaapi 


eo-^t~^«©odi>i>ioo6oi-HOoJ«o»OrH0 05 


00 










JO -JUBO Jai 


1— li— (i— 1 tHi— (i-Hi— lr-( 






CO 

CD 






,-iccirH(Meoooa5Ttico?D<?^cocft«oioo5=oio 


CD 






< 


•aidioniij 


MOice4o"^odo6coi>^odr-Hc4coc4ioo^ 


o 




05 




o 
o 

o 




ooooi>-t^i:^i»io)LOiCio-*io-^-^-<ti-^Tt<eo 


CD 




■IS 






o«ocoooeo(M»Oi— (Osioooosoiooicioeo 


t- 






m 


•Jinsaa 


o <» ai !>•'■<*' o -^ ic eo i-H C4 lo oj «5 «o o to lO* »o 1 
00 t>. CO ■» CO ?o ic lO lo ut> tp ■* CO CO CO •* CO c<i lo 




o 
H 








oscorHsorHOr-iunicot-eot^eoT-KNtMeo 


a> 


00 


o» 






•aidiouiJ,! 


cot4oJ«oo50cococ<iico6odoO'*'i-^i-I.-H 


T— 1 


TJH 


00 
CD 




v> 




O100t^t^«O-^»O'*iC<)'^TtikOe0-^!MC<l(Mi-l 


ira 








t^Oit^lOkCOO-HOlClCt-i-HOKMCOrHCOCO 


'^ 










•JinsaH 


.-JoC^-TlHcd«5i--J.-;<>^eOod'-Hi:OOCOi005rH 
OiOOI>.t-^COlC'^(M'<*'^lO<MCOIM<Mr-lrH 


05 












CO <M 05 (M CO t^ t^ T-l : CD C^ lO "» IM t-H lO •^ rH 


lO 


CO 


■* 






•axdiouiij 


cqt^CJtdl^iOcO'^ •cc3a35^cD'*'0!N«£>0 


CO 


i>^ 


t- 




t~ 




00 CO IC CD IC CO lO CO : CO 1-1 CO CO C<« CO CO rH i-H 


-<J< 








tH IM iC iC CD CO Oi (M : 0^ ^ 0^ la lO lO r-i a> Oi 


"* 










•Jinsaa 


i-5'*cocoTt5cocoi-H :iocooicoo5005icoc5 

00 CD -f CO lO CO lO CO ; CO 1-H <N CO rH CO IN rH 


05 

CO 












co>o-*oc<»cooTj<r-i.-ii-(t^eoic-^t^t^t^ 


?q 


05 


00 






•oidioniij 


O^COM^lNiOiCOCOOOiCOOi-HOlcOt^OOCO 


CO 


CO 




to 




GOOOCOt-t^l:^'*COCOiO'l<'*t^M^COeOCOCO 


CO 




r-T 






CO Tj^ Oi IM CO IM t- C5 00 O CO rH CO i-H i« C<) (T) CO o 










•Jins3H 


oioocio5rHeoo6o5'^c<i'^o6«d'^ioioi> o 

t- 00 00 t- CO t^ •^ lO lO lO ■* ■* CD "^ CO CO CO iM CD 












>OCOrHCOCOCOOJ>-OOlClt^OC<l.— lOOr-HTtlUt) 


iC 


i-H 


CO 






•aidionuj 


(M00t^00a»»COl>-CDC0>OrH-^(M(MC0'-H'* 
0000COI:^t^00COt^l>-I>COt^'>^u:)COCOI>'TtH 


lO 


00 






lO 




t- 




i-T 






iCI:^COt^OO(MCD(MiCCOiOOi— ICOOt^-^iJO 


-* 










•Jinsaa 


osTtHo-^ooococooiocot^ooioioeoiot^ 

l>0000t-t^l>iCU:^t^COiCCOeO'<*'iOii3COC0 


05 












CD 












t^-* : o CO t- oi -^ 00 1^ c<i CO i> 05 CO CO (M o 


05 


00 


CO 






•aidiouud 


CDi-H IcDCOt-^OJcDIM'citN'cDi-HrHTlHOJlOod 


Oi 


-^ 


CO 

r- 1 




■* 




t^ 00 : CD t^ 00 !>• t^ t^ !>. CD •* CO lO IC CD iC lO 


CD 


I— 1 






•*t^ :lCOC0r-llO0100lClCrHCD00C0Tt(,-H 


lO 










•Jtnsaa 


ot5c4 ■•■<j5orHooc<ioicoo6odrHc6o5i>:rH 

cot- .lOCOOOt-t-COiOiOCOlM-^CO'O-^'* 


as 








'looqog 


rHi-l(MCO-<*lTH(Mr-lMCO'<*rH.-l(MeOTH(NCO 


: : 


: 














































2 
« 

o 

1 


i 

a 

« 

>(-H 












































2 


a 


P- 






































fc— 


' t— 


h- H 


01 


o 


-s 








1— < 
1— ll- 


!i- 


< I— 


h- 


' ^Btttt>>>>>>> 














>>(>i!^t^t^t>^>^>-.t^>^6>^>^!^t^>^t-,>->>> 


c 




y 










a> 
























J^ ^ ^ ^ ^ „ ^.^ 


)<_ 


^(_ 


JC 


)C_ 


)C 


JC 


)C 


JC- 


JC 


)C_ 


)C 


)C 


)C 


)C 


)C 


)C 


)0 


O 


Ph 


k^H 



TEE INFLUENCE OF THE ENVIRONMENT 73 

After this admirable array of facts Dr. Rice jumps rather 
hastily to this speculative conclusion : " The facts here presented, 
in my opinion, will admit of only one conclusion, viz., that the 
results are not determined by the methods employed, but by the 
ability of those who use them. In other words, the first place 
must be given to the personal equation of the teacher, while 
methods and devices play a subordinate part." 

This statement should have been based upon a demonstration 
of a high coefficient of correlation between the measure of a grade 
in spelling and the measure of its teacher in ability, or of a great 
increase in variability in spelling ability as we pass from the 
children taught by one teacher to the children taught by 10 or 
20 different teachers. I calculate that if the reliabilities of Dr. 
Rice's eighth grade averages are what they would seem to be from 
tests made in eighth grades by myself and my students,* the dif- 
ferences amongst them are not much greater than we would ex- 
pect by the law of chance if the teaching were in all cases equally 
efficient. The average deviation from their mean of the 12 eighth 
grades which were tested in the first half of the year is 1.9 ; 
that of the 13 eighth grades tested in the last half of the year is 
2.6; the average deviation by pure chance of 12 eighth grades of 
40 students each would be 1.9, the variability of individuals 
being 12.2. In the case of the eighth grades then we may need no 
cause at all for the differences amongst schools save the inaccuracy 
of the averages due to the small number of cases. 

Dr. Rice measured the arithmetical ability of some 6,000 
children in 18 different schools in 7 different cities, t The results 
of these measurements are summarized in table VII. This table 
" gives two averages for each grade as well as for each school as 
a whole. Thus, the school at the top shows averages of 80.3 and 
83.5, and the one at the bottom, 25.2 and 31.8. The first repre- 
sents the percentage of answers which were absolutely correct ; the 
second shows what per cent, of the problems were correct in prin- 
ciple, i. e., the average that would have been received if no me- 
chanical errors had been made. The difference represents the 

* These give a variability of 12.2 amongst the individuals of the grade, 
t See pp. 29G-298 of the Forum, October-December, 1002, for the tests 
given. 



74 EDUCATIONAL PSYCHOLOGY 

percentage of mechanical errors, which, I believe, in most in- 
stances, makes a surprisingly small appearance." 

From these results Dr. Eice seeks the causes of excellence in 
arithmetical work as in the case of spelling by comparing the 
condition in the successful schools with those in the unsuccessful. 
He deals seriatim with (1) the home environment of the pupils; 
(2) the size of the classes; (3) the age of the children; (4) the 
time of day of the test; (5) the time devoted to arithmetic in 
the school; (6) the amount of home work required; (7) the 
methods of teaching; (8) teaching ability as represented by a 
combination of education, training and the personality of the 
teacher; (9) the course of study; (10) the superintendent's 
training of teachers; (11) the establishment of demands in re- 
gard to results; (12) the testing for results (a) by teachers 
alone, (b) by teachers and superintendents, (c) by principals, 
(d) by principals and superintendents. 

He finds that the work depends upon the method of testing 
for results, that teachers and pupils do about what is demanded of 
them, and that the best work appears when the superintendent, in 
connection with principals of schools, tests and rates the work of 
the classes. 

The following are samples of the reasoning by which he 
eliminates one after another of the possible causes : 

Home Environment. 

If the part that is played by the home environment should be as im- 
portant as it is generally supposed to be, we should, of course, expect to 
find that the schools represented in the upper part of the table had been 
attended by children from cultured homes, while those in the lower part had 
been attended by those whose home environment was very poor. However, if 
a line should be dra-\vn across the middle of the table, and the schools above 
it compared with those below, such a condition would not be found. Indeed, 
careful inspection would show that the odds were certainly not in favor of 
the "aristocratic" districts. Of the eighteen schools, three in particular 
are representative of the latter, and the best of these secured the tenth 
place, while the others ranked eleventh and sixteenth, respectively. The 
school that ranked seventh was distinctively a school of the slums. That 
is. to say, the school laboring \mder the poorest conditions in respect to 
home environment obtained a better standing than any one of the so-called 
aristocratic schools. The building which stands fifth is representative of 
conditions just a shade better than those of the slums. And when I add 
that, from the standpoint of environment, the schools of City I. did not 



THE INFLUENCE OP THE ENVIRONMENT 75 

average a single degree better than those of Cities VI. and VII., I have said 
enough to show that the poor results secured in the latter cities cannot be 
condoned on the ground of unfavorable environment. Thiis, as in spelling, 
so in arithmetic, this moimtain, upon close inspection, dwindles down to the 
size of a molehill. 

Size of Classes. 

Equally surprising, if indeed not more incredible, may appear the state- 
ment that no allowance whatever is to be made for the size of the class 
in judging the results of my test. I shall not enter into the details in 
regard to this point, but will dismiss it with the remark that the number 
of pupils per class was larger in the highest six schools than it was in the 
schools of City VI., and that the classes were exceptionally small in the 
school that stands at the lower end. 

Age of Pupils. 

His argument is here too lengthy to quote and is rather awk- 
ward, but sufficiently proves that the differences between schools 
could have been due only in a very slight degree if at all to differ- 
ences in the ages of the pupils. The obvious way to eliminate age 
is to compare a group from city VI. or VII. with a group iden- 
tical in age and grade from city I. or III. 

Time of Day. 

This can not be the cause of much of the difference found for 
within any one city the time of day of the test makes little 
difference. 

The Time Devoted to Arithmetic in the School. 

A glance at the figures will tell us at once that there is no direct rela- 
tion between time and result; that special pressure does not necessarily 
lead to success, and, conversely, that lack of pressure does not necessarily 
mean failure. 

In the first place, it is interesting to note that the amount of time 
devoted to arithmetic in the school that obtained the lowest average — 25 
per cent. — was practically the same as it was in the one where the highest 
average — 80 per cent. — was obtained. In the former the regular time for 
arithmetic in all the grades was forty-five minutes a day, but some addi- 
tional time was given. In the latter the time varied in the different classes, 
but averaged fifty-three minutes daily. This shows an extreme variation in 
results under the same appropriation of time. 

Looking again toward the bottom of the list, Ave find three schools with 
an average of 36 per cent. In one of these, insufficient pressure might be 
suggested as a reason for the unsatisfactory results, only thirty minutes 
dailv having been devoted to arithmetic. The second school, however, cave 
forty-eight, while the third gave seventy-five. This certainly seems to indi- 



I 



76 EDUCATIONAL PSYCHOLOGY 

cate that a radical defect in the quality of instruction cannot be offset by 
an increase in quantity. 

If we now turn our attention from the three schools just mentioned and 
direct it to three near the top — Schools 2, 3, and 4, City I. — we find the 
conditions reversed; for while the two schools that gave forty-five minutes 
made averages of 64 per cent, and 67 per cent., respectively, the school that 
gave only twenty-five minutes succeeded in obtaining an average of 69 per 
cent. This would appear to indicate that while, on the one hand, nothing 
is gained by an increase of time where the instruction in arithmetic is faulty, 
on the other hand, nothing is lost by a decrease of time, to a certain point, 
where the schools are on the right path in teaching the subject. Perhaps 
the most interesting feature of the table is the fact that the school giving 
twenty-five minutes a day came out within two of the top, while the school 
giving seventy-five minutes daily came out practically within one of the 
bottom. 

The Amount of Home Work Required. 

The greatest amount of home work was required in the 
lowest ranking city while it had been practically abandoned in 
the first five schools of the table. 

In the other cases the facts are given more vaguely, and in 
his presentation of positive evidence that differences in super- 
vision by tests are the leading causes of the differences in achieve- 
ment of the different schools, Dr. Rice seems to reach his 
conclusion simply from observing (1) that all conditions in 
City VI. were favorable save that examinations were given only 
by the teacher, (2) that in City VII. the examinations were 
given by the teacher and perfunctorily by the superintendent, while 
(3) in City I. the superintendent with the principals took pains in 
setting the tests. It seems highly probable that the cause he alleges 
is a real and important one, though even his own facts show the 
cooperation of other causes. This I take it he does not mean to 
deny. 

In these two studies the argumentation would be much clearer, 
neater and more precise if put as follows : the coefiicients of 
correlation or association for knowledge of arithmetic with size of 
classes, age of children, time devoted, amount of home work re- 
quired, etc., are respectively a, b, c, d, e, etc. A zero coefficient 
would mean no causal relation and the amount of any coefficient 
would measure the relative importance of the factor in question as 
a cause or co-result of some common cause. 



THE INFLUENCE OF THE ENVIRONMENT 77 

The reader may note in the results some interesting facts 
which Dr. Rice has not explicitly mentioned. For instance in 
arithmetic the resemblance between different grades of the same 
school is .64 while in spelling it is only .16. The variation 
amongst schools in arithmetic increases from .260 in the fourth 
grade to .504 in the eighth, while in spelling it decreases from 
.114 to .031.* These measurements show clearly that efficiency 
in arithmetic is dependent upon the spirit and work of a school 
to a far greater extent than is spelling. 

The Method of Action of the Environment. 

I shall here present a descriptive account which is frankly a 
matter of speculation rather than proof. It is in brief that the 
environment changes mental traits only by: 

1. Furnishing or withholding conditions for the brain's growth 
and actions. 

2. Furnishing or withholding adequate stimuli to arouse the 
action of which the brain is by original nature or previous action 
capable. 

3. Reinforcing some and eliminating others of these activi- 
ties in consequence of the general law of selection in mental life.f 

According to this description we should look upon the mental 
life of an individual as developing in the same way that the ani- 
mal or plant kingdom has developed. As conditions of heat 
and food-supply have everywhere been the first requisite to 
and influence on animal life, so the physiological conditions 
of the brain's activities are the first modifiers of feeling and 
action. As the stimuli of climate, food, unknown chemical and 
electrical forces and the rest have been the means of creating 
variations in the germs or of stimulating to action the inner 
tendency of the germs to vary and so have rendered possible the 

* These figures are the coefficients of variability. It is doubtful whether 
Dr. Rice's tests in different grades were commensurate and consequently 
whether any comparison of variability can be strictly accurate. 

tin all animals capable of profiting by training any act wliich in a 
given situation brings pleasure becomes thereby more closely associated with 
that situation so that when that situation recurs the act will recur also. 
An act that brings pain becomes dissociated from the situation and less 
likely to recur. 



78 EDUCATIONAL PSYCHOLOGY 

production of millions of different animal types, so the sights 
and sounds and smells of things, the words and looks and acts of 
men, the utensils and machinery and buildings of civilization, its 
pictures and music and books, awake in the mind new mental 
varieties, new species of thoughts and acts. In a score of years 
from birth the human rnind like the animal world originates its 
universe of mental forms. And as in the animal kingdom many 
of these variations fail to fit the conditions of physical nature and 
die after a generation or two, so in any one of us many of the 
mental forms produced are doomed to a speedy disappearance in 
consequence of their failure to fit outside events. The elimination 
of one species by others in the animal world is again paralleled by 
the death of those thoughts or acts which are out of harmony 
with others. Species of thoughts like species of animals prey upon 
one another in a struggle in which survival is the victor's reward. 
Further just as species of animals fitted to one environment perish 
or become transformed when that environment changes, so mental 
forms fitted to infancy perish or are transformed in school life; 
mental forms fitted to school life perish in the environment of 
the workaday world; and so throughout the incessant changes 
of a mind's surroundings. In mental life resulting pain or dis- 
comfort is the cause of the extinction of a species. The condi- 
tion of a man's mind at any stage in its history is then, like the 
condition of the animal kingdom at any stage in the history of 
the world, the result not only of the new varieties that have ap- 
peared, but also of a natural selection working upon them. The 
tale of a human mind's progress is the tale of the extinction of 
its failures. 

Possibility of existence, stimuli to variations, selection by 
elimination: these words that describe the action of the environ- 
ment on animal life are equally competent to tell the record of a 
human life. 

The substitution of these simple names for the real types of 
influence in place of the indefinite and unsuitable terms, maturity, 
training, practice, imitation, culture, discipline, etc., leads to a 
number of interesting suggestions about the description and even 
explanation of changes in human nature which must, however, be 
left to the reader's own inferences. I will mention only the terms 



THE INFLUENCE OF THE ENVIRONMENT 79 

in whicli I should describe tiie work of education, following the 
analysis just given. The work of education is : 

1. To supply the needs of the brain's healthy growth and to 
remove physiological impediments to it. 

2. To provide stimuli to desirable mental variations and to 
withhold stimuli from the undesirable. 

3. To make the outcome of desirable activities pleasurable and 
to inhibit their opposites by discomfort. 

The three chief practical problems of education would thus 
be those of hygiene, of opportunity and of incentives and de- 
terrents. 



CHAPTER VIII. 

THE INFLUENCE OF SPECTAl, FORMS OF TRAINING UPON MORE 

GENERAL ABILITIES. 

One of the quarrels of the educational theorists concerns the 
extent to which special forms of training improve the general 
capacities of the mind. Does the study of Latin or of mathe- 
matics improve one's general reasoning powers ? Does labora- 
tory work in science train the power of observation for all sorts 
of facts ? Does matching colored sticks educate the senses for all 
sorts of discriminations ? 

The problem, which is clearly one of psychological fact, may 
be best stated in psychological terms as follows: How far does 
the training of any mental function improve other mental func- 
tions ? In less technical phrase. How far does an ability, say 
to reason, acquired with data Aj extend also to data B, C, D, etc ? 

1^0 one can doubt that all of the ordinary forms of home or 
school training have some influence upon mental traits in addition 
to the specific changes which they make in the particular function 
the improvement of which is their direct objecf. On the other hand 
no careful observer would assert that the influence upon the other 
mental traits is comparable in amount to that upon the direct 
object of training. By doubling a boy's reasoning power in arith- 
metical problems we do not double it for formal grammar or 
chess or economic history or theories of evolution. By tripling 
the accuracy of movement in fingering exercises we do not triple 
it for typewriting, playing billiards or painting. The gain of 
courage in the game of football is never equalled by the gain in 
moral courage or resistance to intellectual obstacles. The real 
question is not, ' Does improvement of one function alter others V 
but, ' To what extent and how does it V 

The answer which I shall try to defend is that a change in one 
function alters any other only in so far as the two functions have as 
factors identical elements. The change in the second function is 
in amount that due to the change in the elements common to it and 
the first. The change is simply the necessary result upon the 

80 



THE INFLUENCE OF SPECIAL TRAINING 81 

second function of the alteration of those of its factors which 
were elements of the first function and so were altered by its 
training. To take a concrete example, improvement in addition 
will alter one's ability in multiplication because addition is abso- 
lutely identical with a part of multiplication and because certain 
other processes, e. g., eye movements and the inhibition of all save 
arithmetical impulses, are in part common to the two functions. 

Chief amongst such identical elements of practical importance 
in education are associations including ideas about aims and ideas 
of method and general principles, and associations involving ele- 
mentary facts of experience such as length, color, number, which 
are repeated again and again in differing combinations. 

By identical elements are meant mental processes which have 
the same cell action in the brain as their physical correlate. It is 
of course often not possible to tell just what features of two 
mental abilities are thus identical. But, as we shall see, there is 
rarely much trouble in reaching an approximate decision in those 
cases where training is of practical importance. 

The standard psychology and pedagogy books with few excep- 
tions answer our questions in a manner very different from this. 
They extend the influence of any special form of discipline much 
farther, and describe its manner of operation only by vague and 
I think meaningless phrases.* 

In place of any descriptive account I shall give a number of 
quotations picked almost at random from all the statements about 
the influence of special training on general ability made in some 
fifty representative books on psychology and pedagogy. These 
will represent fairly the prevailing attitude. 

Systematic treatises on psychology, with two or three excep- 
tions, neglect the functional aspect of mental life and so do not 
furnish any apt quotations. Their implied point of view how- 
ever is, again with one or two exceptions, that alterations in mental 
powers are alterations in the general facility of attention, reason- 
ing, etc. 

* The leading exception in psychology is James' ' Principles of Psychol- 
ogy,' and in pedagogy is the Herbartian literature. The often correct con- 
clusions of the latter are however based upon defective principles. 



82 EDUCATIONAL PSYCHOLOGY 

Books on applied psychology express this implication out- 
right, and books on education carry it to an amazing extreme. 
The following quotations represent accurately a widespread 
opinion : 

Since the mind is a unit and the faculties are simply phases or mani- 
festations of its activity whatever strengthens one faculty indirectly strength- 
ens all the others. The verhal memory seems to be an exception to this 
statement, however, for it may be abnormally cultivated without involving 
to any profitable extent the other faculties. But only things that are rightly 
perceived and rightly understood can be rightly remembered. Hence what- 
ever develops the acquisitive and assimilative powers will also strengthen 
memory; and, conversely, rightly strengthening the memory necessitates the 
developing and training of the other powers. ( R. N. Roark, ' Method in 
Education,' p. 27.) 

It is as a means of training the faculties of perception and generaliza- 
tion that the study of such a language as Latin in comparison with English 
is so valuable. (C. L. Morgan, 'Psychology for Teachers,' p. 186.) 

Arithmetic, if judiciously taught, forms in the pupil habits of mental 
attention, argumentative sequence, absolute accuracy, and satisfaction in 
truth as a result, that do not seem to spring equally from the study of any 
other subject suitable to this elementary stage of instruction, (Joseph Payne, 
' Lectures on Education,' Vol. I., p. 260. ) 

By means of experimental and observational work in science, not only 
will his attention be excited, the power of observation, previously awakened, 
much strengthened, and the senses exercised and disciplined, but the very 
important habit of doing homage to the authority of facts rather than to the 
authority of men, be initiated. {Ibid., p. 261.) 

. . . The study of the Latin language itself does eminently discipline 
the faculties and secure to a greater degree than that of the other subjects 
we have discussed, the formation and growth of those mental qualities which 
are the best preparatives for the business of life — whether that business is 
to consist in making fresh mental acquisitions or in directing the powers 
thus strengthened and matured, to professional or other pursuits. (Ibid., 
p. 264.) 

I wish to understand by mental discipline the exercise of some faculty 
of the mind, which results in increasing the power or readiness of that 
faculty. (E. H. Babbitt, p. 126, of 'Methods of Teaching the Modern Lan- 
guages.') 

The faculty which is by far the most important of the human mind, 
and which we most earnestly strive to develop and perfect in our pupils, is 
the faculty of judgment, or the reasoning faculty (I am not trying to be 
psychologically exact), the faculty whose perfection gives what we call a 
logical mind — a mind which has a ready perception of the relations of 
things and is not likely to be misled by false reasoning. (Ibid., p. 127.) 

The most valuable thing in the way of discipline which comes from a 
study of a foreign language is its influence in improving the pupil's com- 
mand of his own. Of course this means the improvement in general judg- 



TEE INFLVEXCE OF SPECIAL TRAINING 83 

ment and discrimination which is evinced by a finer linguistic sense. . . . 
(Ibid., p. 129.) 

Let us now examine in detail the advantages which a person who has 
taken the ordinary Bachelor's degree has derived from the study of classics. 
Aside from the discipline of the will, which comes from any hard work, we 
find the following: (1) His memoiy for facts has been strengthened by 
committing paradigms and learning a new vocabulary. (2) He has been 
obliged to formulate pretty distinctly a regular system of classified facts — 
the facts which form the material of the grammar — classified in due form 
under chapter, section, subsection and so on. This means that he has learned 
to remember things by their relations — a power which can hardly be acquired 
without practice in forming or using such classified systems. (3) He has 
had his judgment broadened and strengthened by constant calls upon it to 
account for things which cannot be accounted for without its exercise. (Ibid., 
p. 130.) 

Correct use of the language is always to be insisted upon. This espe- 
cially in the oral exercises makes concentration imperative and serves in an 
eminent degree as a disciple of the mil. . . . Practice in the use of a foreign 
language cultivates the imagitiation. ... I have not mentioned the cultiva- 
tion of the memory. The study of modern languages offers wide opportunity 
not only for the exercise of verbal memory, but especially for the rational 
use of this important power, by means of association, comparison, discrim- 
ination. (A. Lodeman, 'Methods of Teaching Modern Languages,' pp. 104- 
105.) 

The value of the study of Gterman ' lies in the scientific study of the 
language itself, in the consequent training of the reason, of the powers of 
observation, comparison and synthesis; in short, in the upbuilding and 
strengthening of the scientific intellect.' (Calvin Thomas, 'Methods of 
Teaching Modern Languages,' p. 27.) 

[Advantages resulting from the teaching of draxving.] The visual, men- 
tal and manual powers are cultivated in combination, the eye being trained 
to see clearly and judge accurately, the mind to think, and the hand to 
record the appearance of the objects seen, or the conceptions formed in the 
mind. Facility and skill in handicraft, and delicacy of manipulation, all 
depend largely upon the extent to which this hand and eye training has 
been fostered. The inventive and imaginative faculties are stimulated and 
exercised in design, and the graphic memory is strengthened by practice in 
memory drawing. The aesthetic judgment is brought into use, the power of 
discerning beauty, congruity, proportion, symmetry, is made stronger; and 
the love of the beautiful, inherent more or less in mankind, is greatlj'^ in- 
creased. (J. H. Morris, 'Teaching and Organization' (edited by P. A. Bar- 
nett), pp. 63-64.) 

As regards the first point, it may be noted that the pursuit of mathe- 
matics gives command of the attention. A successful study increases or 
creates the power of concentrating the thoughts on a given subject and of 
separating mixed and tangled ideas. The habits of mind formed by means 
of this one set of studies soon extend llioir iiilluoncc to otlu>r studies and 
to the ordinary pursuits of life. The man or woman who lias Ix'cn drilled by 
means of mathematics is the better able to select from a number of possible 



84 EDUCATIONAL PSYCHOLOGY 

lines which may be suggested that which is easiest or most direct to attain 
a desired end. 

The second purpose of this study is the one which has been most uni- 
versally acknowledged in all ages, namely, the strengthening and training 
of the reasoning powers. (R. Wormell, 'Teaching and Organization' (edited 
by P. A. Barnett), p. 78.) 

We may conclude this list by quotations from a recent 
inaugural address at a great American college and from the 
reasons given by a number of presidents of colleges to the question, 
' Wliy go to college V 

" We speak of the ' disciplinary ' studies . . . having in our thought 
the mathematics of arithmetic, elementary algebra, and geometry, the Greek- 
Latin texts and grammars, the elements of English and of French or Ger- 
man. . . . The mind takes fiber, facility, strength, adaptability, certainty of 
touch from handling them, when the teacher knows his art and their power. 
The college . . . should give . . . elasticity of faculty and breadth of vision, 
so that they shall have a surplus of mind to expend. . . ." (Woodrow Wil- 
son, Science, November 7, 1902.) 

Thomas J. Conaty, Rector of the Catholic University of America : " I 
would say, in one word, for discipline." 

Nathaniel Butler; President of Colby College : " It has been well said 
that an educated man has a sharp ax in his hand and an uneducated man 
a dull one. I should say that the purpose of a college education is to 
sharpen the ax to its keenest edge." 

H. M. MacCracken, Chancellor of New York University : " He will pos- 
sess a better disciplined mind for whatever work of life he may turn his 
attention to." 

Timothy Dwight, late President of Yale University: "Such an educa- 
tion is the best means of developing thought power in a young man, and 
making him a thinking man of cultured mind." 

The last four statements appeared in the Penn Charter Maga- 
zine, at just what date I am unable to ascertain. 

It is clear that the common view is that the words accuracy, 
quickness, discrimination, memory, observation, attention, con- 
centration, judgment, reasoning, etc., stand for some real and 
elemental abilities which are the same no matter what material 
they work upon ; that these elemental abilities are altered by special 
disciplines to a large extent ; that they retain those alterations when 
turned to other fields ; that thus in a more or less mysterious way 
learning to do one thing well will make one do better things that 
in concrete appearance have absolutely no community with it. 

The mind is regarded as a machine of which the different 
faculties are parts. Experiences being thrown in at one end, per- 



THE INFLUENCE OF SPECIAL TRAINING 85 

ception perceives them, discrimination tells them apart, memory 
retains them and so on. By training the machine is made to work 
more quickly, efficiently and economically with all sorts of experi- 
ences. Or in a still cruder type of thinking the mind is a storage 
battery which can be loaded with will power or intellect or judg- 
ment, giving the individual ' a surplus of mind to expend.' Gen- 
eral names for a host of individual processes such as judgment, 
precision, concentration are falsely taken to refer to pieces of 
mental machinery which we can once for all get into working order, 
or still worse to amounts of some thing which can be stored up in 
bank to be drawn on at leisure. 

The chapter upon the relationships of mental abilities proved 
that there was every reason to disbelieve in the existence of any 
such truly general abilities, that the general words memory, atten- 
tion, etc., represented a summation of or abstraction from a host of 
particular capacities largely independent of each other. The argu- 
ment from the static independence of mental functions must not 
be pressed too far in arguing that they are functionally independ- 
ent. Two traits might show little or no correlation and yet train- 
ing of one might improve the other. On the other hand, two 
traits might show perfect correlation and yet one be in no wise in- 
fluenced by alteration in the other. What the static independence 
of mental traits does prove is the specialization of the mind, the 
general absence of necessary relationships. It thus destroys two 
of the a priori arguments for the common view of functional de- 
pendence. The next section of this chapter will demonstrate that 
in point of fact learning to do one thing well has a much less 
influence upon one's other abilities than these authors have led 
teachers and others to believe. 

Only a few experiments have been made upon the spread of 
ability from the one function trained to others. The studies of 
James,"" Gilbert and Fracker,f Thorndike and Woodworth,:}: 
Judd,§ and Bair|l which will be summarized in this chapter are 

♦'Principles of Psychologj^' Vol. I., pp. 667-668. 

t University of Iowa, ' Studies in Psychology',' Vol. I. 

% Psychological Review, May, July and November, 1901, Vol. VIII. 

§ Psychological Review, Vol. IX., ])|i. 27-39. 

II Psychological Review, Monograph Supplement, No. 19, pp. 25, 28, 64-67. 



86 EDUCATIONAL PSYCHOLOGY 

the only studies that deal specifically with this question. I shall 
however describe also the studies of Volkmann,* Scripture, Smith 
and Brown,f Davis,:}: and Woodworth,§ upon cross-education or 
the extent to which training one organ of the body improves the 
bilaterally symmetrical organ. Their results have been improp- 
erly used as evidence upon our question. We must therefore 
examine them. 

Volkmann found that by practice of the left arm in discrim- 
ination until an initial ability of 23.6 improved to 11.2, the right 
arm without any practice showed an improvement from 26.4 to 
15.7. Similar results were found for other cases of cross-educa- 
tion and for the spread of improvement in discrimination of touch 
at certain spots on the skin to neighboring spots. 

Scripture, Smith and Brown found that improvement in 
strength of grip in one arm in consequence of its exercise was in 
one subject accompanied by 80 per cent, as much improvement 
in the other arm. Only one subject took the practice. In pre- 
cision the gain was 2 per cent, greater in the unpracticed arm, in 
the one individual studied. Davis found that the improvement in 
•quickness of tapping with the right toe due to its practice was 
•■accompanied by 151 per cent, as much improvement in the left 
loot, 100 per cent, as much in the right hand and 83 per cent. 
as much in the left hand. Exercise of the biceps of the right 
arm was followed by increase of the number of flexions endurable 
to the amount of 433, 950, 900, 300, 200 and 532 per cents, in the 
six subjects of the experiment. The increases for the left arm 
consequent upon the exercise of the right were respectively 200, 
37, 60, 12, 300, 553. Practice in lunging at a target with a foil 
100 times with the right hand was followed by an improvement in 
the left about three fourths as great as in the right (six subjects 
gave ratio of left arm to right arm improvement 1.14^ 1.03, .80, 
.54, .99 and .11 respectively). Unilateral practice in gripping a 
dynamometer was followed by improvement of both sides. The 
ratios of improvement in the unpracticed to improvement in the 

*'Bericht der Kgl.-sachs. Ges. d. Wiss., Math.-phys. CI.,' 1858; X., 38. 

IfYale Studies, Vol. 2. 

t Yale Studies, Vols. 6 and 8. 

§ Psychological Review, Monograph Supplement, No. 13, p. 105. 



THE INFLUENCE OF SPECIAL TRAINING 87 

practiced side ranged for the 25 subjects from — 44 per cent, to 
411 per cent, the median value being — 3 per cent. 

Woodworth measured the influence of practice of the left hand 
in the accuracy of hitting a dot upon the ability of the other hand 
in the same performance. The results were as follows: 

Accuracy at 40 motions per minute. At 120. At 200. 

Left hand: Before 3.5 4.2 8.3 

After 0.4 3.8 7.2 

Right hand: Before 3.1 3.9 7.1 

After 0.7 3.8 6.6 

In repeating these experiments it seemed to the writer certain 
that the important cause of improvement was the acquisition of 
skill in moving the eyes quickly and accurately. This would of 
course be an identical feature of both trained and tested acts. 

These facts are not strictly relevant to our problem, for the 
influence of training one part of the body in a certain task upon 
the efficiency of the bilaterally symmetrical half of the body in 
the same task is a very peculiar case. The sensations from or 
movements of any pair of bilaterally symmetrical organs are in 
a way quite different from those of a pair of organs taken at ran- 
dom. It is therefore fallacious to connect the facts of cross- 
education with such inferences as the following : " The capa- 
bility of concentrating attention on a certain point in question, 
in whatever field it is acquired, will show itself efficacious in all 
others." (Stumpf, " Tonpsychologie," 1883, I., 81, quoted by 
Davis, Yale Studies, 6, p. 46.) 

" Development of will power in connection with any activity 
is accompanied by a development of will power as a whole." 
(Scripture, Psy. Rev., VI., 165, quoted by Davis, Yale Studies, 
No. 6, p. 47.) 

" Will power and attention are educated by physical training. 
When developed by any special act, they are developed for all 
acts." (W. W. Davis, Yale Studies, Is^o. 8, p. 103.) 

These statements are unjustifiable: (1) Because they imply 
that any two functions are related as are sensations or movements 
of one organ with identical ones from the bilaterally symmetrical 
one. This is utterly false. (2) Because they imply that the 
amount of improvement of ' attention ' or ' will power ' in the 



88 EDUCATIONAL PSYCHOLOGY 

one organ is equaled in the case of the other. It is not- (3) 
Because they make no adequate effort to discover whether the 
amount of improvement that is common to both is not due entirely 
to identical elements of a concrete sort such as acquaintance with 
the oneness and twoness feelings in the case of touches with com- 
pass point or points, or actual contractions of both muscles when 
nominally only one is being exercised, or the habit of gripping 
the dynamometer in a certain way and suddenly. These are 
veroB causae and may be sufficient to explain the facts. The phe- 
nomena of cross-education are an interesting chapter in experi- 
mental psychology but are not fair samples of the general facts 
we seek. Nor is their significance at all clear. 

The first group of studies mentioned on page 85 will give a 
fair idea of the influence of training in one function upon the con- 
dition of another if we bear in mind: (1) That in all the ex- 
periments the two functions were very closely similar, were in 
fact such as the psychologies and pedagogies generally would re- 
gard as identical, and (2) that the individuals who took the train- 
ing were of a gifted class compared with people in general and 
would be much more likely than they to use the ideas and habits 
acquired in one field when tested in another. 

James took measurements of the ability to memorize one kind 
of verse before and after a fixed amount of training with a differ- 
ent kind of verse. The results were : 

Time before Training. Amount of Training. Time after Training. 

Subject 1 131 5/6 First book of ' Paradise 151 1/2 

Lost' 

Subject 2 14.75 416 lines of German poetry 14.54 

Subject 3 13 26/60 ? 12 16/60* 

Subject 4 3.67 450 lines 3.04* 

Subject 5 14.34 ? 14.55 

The amounts of improvement in the function especially trained 
are not given. 

In Gilbert and Tracker's experiments two subjects were tested 

for their quickness in moving the finger: (1) When they heard 

a certain sound, (2) when they felt a certain electric shock, (3) 

* Subjects 3 and 4 had in the tests before and after training 32 and 30 
days of training which, as Professor James thinks, gave too much chance 
for special practice. 



THE INFLUENCE OF SPECIAL TRAINING 89 

when they felt a certain blow, and (4) when they saw a blue sur- 
face. In all these cases they were warned two seconds before the 
stimulus and no other stimuli could be confused with it. They 
were also tested for their quickness in moving the finger at these 
same stimuli when either the given sound or one less loud, either 
the given shock or one less intense, either the given blow or one 
less hard, either the blue or a red might appear. They were then 
trained for a number of days in quickness in reacting to the 
sound, (A) when only it was given, and (B) when either it or the 
weaker sound might be given. They were then tested as before. 
The results showed improvement in all cases save one with one 
observer. One observer was trained only in (A), He improved 
markedly in the corresponding tests, but not so much as the others 
in the second set of tests. The small number of cases and the 
low correlation between an individual's improvement in the special 
act trained and in his gain in the other acts tested make the 
argument from the amount of this gain insecure. It was how- 
ever large, as will be seen from table VIII. It is obvious that the 
functions trained and the functions tested contained many identi- 
cal elements, the operations being absolutely identical with the 
exception of the kind of a signal used. 

TABLE VIII. (Table VII. of the Okiginal Abticle). 
Pee Cent, of Time Gained bt Pbactice. 











Reaction. 


Reaction with 


Discrimination. 




Discrimination. 








J£ 


JE 


T 


S 


h 


e 


t 


s 


h' 


e' 


I' s' 


J. 


A. 


C. 


12 





17 


3 


53 


35 


9 


14 


92 


78 


26 


G. 


C. 


F. 


2.3 


21 


10 


45 


47 


60 


38 


34 


83 


64 


56 18 


J. 


C. 


P. 


13 


16 


6 


11 


14 


24 


4 


19 


18 


35 


22 26 



J. C. p. was practiced only in reaction time, while the other two were 
practiced in both reaction and reaction with discrimination and choice. All 
figures of the above table represent per cent, of gain by practice. The O's in 
the second and eleventh columns really mean losses. 

Judd's experiments were too narrow and of too technical a 
nature to be fully described here. The important results for our 
purpose were that an improvement in the direction of attention and 
in the character of eye movements caused one observer to im- 
prove more quickly than he would otherwise have done in a closely 
similar task, but caused in another observer a fixed habit which 



90 EDUCATIONAL PSYCHOLOGY 

absolutely prevented him from improving in the similar task at 
all. (Psy. Rev., IX., pp. 27-39.) 

Thorndike and Woodw^orth made a great variety of experi- 
ments upon the result of training in estimating areas, lengths and 
weights of certain shape and size upon the ability to estimate areas, 
lengths and weights similar in shape but different in size, differ- 
ent in shape but similar in size, different in both shape and size. 
A still more extensive series of experiments measured the influence 
of training in various forms of observation or perception upon 
slightly different forms. Only a few samples of their measure- 
ments can be given here. 

Individuals practiced estimating the areas of rectangles from 
10 to 100 sq. cm. in size until a very marked improvement was 
attained. The improvement in accuracy for areas of the same 
size but of different shape due to this training was only 44 per 
cent, as great as that for areas of the same shape and size. For 
areas of the same shape but from 140-300 sq. cm. in size the 
improvement was 30 per cent, as great. For areas of different 
shape and from 140-400 sq. cm. in size the improvement was 52 
per cent, as great. 

Training in estimating weights of from 40—120 grams re- 
sulted in only 39 per cent, as much improvement in estimating 
weights from 120 to 1800 grams. Training in estimating lines 
from .5 to 1.5 inches long (resulting in a reduction of error to 25 
per cent, of the initial amount) resulted in no improvement in the 
estimation of lines 6-12 inches long. 

Training in perceiving words containing e and s gave a certain 
amount of improvement in speed and accuracy in that special 
ability. In the ability to perceive words containing i and t, s and 
p, c and a, e and r, a and n, 1 and o, misspelled words and A's, 
there was an improvement in speed of only 39 per cent, as much 
as in the ability specially trained, and in accuracy of only 25 per 
cent, as much. Training in perceiving English verbs gave a re- 
duction in time of nearly 21 per cent, and in omissions of 70 
per cent. The ability to perceive other parts of speech showed a 
reduction in time of 3 per cent., but an increase in omissions of 
over 100 per cent. 

These experiments showed very clearly the influence of: (1) 



THE INFLUENCE OF SPECIAL TRAINING 91 

The acquisition during special training of ideas of method of 
general utility and also (2) of facility with certain elements that 
appeared in many other complexes. Instances of (1) are learning 
in the 10-100 cm. training series that one has a tendency to over- 
estimate all areas and consciously making a discount for this ten- 
dency, no matter what the size or shape of the surface may be; 
learning to look especially for the less common letter (e. g., s in the 
case of e-s words, p in the case of s-p words) in the training series 
and adopting the habit for all similar work ; learning to estimate 
areas in comparison with a mental standard rather than the objec- 
tive 1 sq. cm., 25 sq. cm. and 100 sq. cm. squares which each 
experimenter had before him (after one gets mental standards 
of the areas he judges more accurately if he pays no attention 
whatever to the objective standards). An instance of (2) is the 
uniform increase of speed of eye movements in all the perception 
tests through training in one, an increase often gained at the 
expense of accuracy. 

In the opinion of the authors these experiments show that: 

" Improvement in any single mental function need not improve 
the ability in functions commonly called by the same name. It 
may injure it. 

" Improvement in any single mental function rarely brings 
about equal improvement in any other function, no matter how 
similar, for the working of every mental function-group is con- 
ditioned by the nature of the data in each particular case. 

" The very slight amount of variation in the nature of the 
data necessary to affect the efficiency of a function-group makes 
it fair to infer that no change in the data, however slight, is with- 
out effect on the function. The loss in the efficiency of a function 
trained with certain data, as we pass to data more and more 
unlike the first, makes it fair to infer that there is always a point 
where the loss is complete, a point beyond which the influence of 
the training has not extended. The rapidity of this loss, that is, 
its amount in the case of data very similar to the data on which 
the function was trained, makes it fair to infer that this point is 
nearer than has been supposed. 

" The general consideration of the eases of retention or of loss 
of practice effect seems to make it likely that spread of practice 



92 EDUCATIONAL PSYCHOLOGY 

occurs only where identical elements are concerned in the influenc- 
ing and influenced function." 

Bair made several experiments on the influence of practice 
in forming certain associative habits upon the ability in certain 
different habits. I summarize his statements here. 

Six keys of a typewriter are labeled with six symbols (let- 
ters or figures). Fifty-five of these letters or figures (in chance 
order) are now shown one by one and the subject on seeing one 
taps the corresponding key. The time taken to tap out the series 
is recorded. Six different symbols are then used with a new series 
composed of them and the subject's time record is taken as before. 
This is kept up until twenty different sets of symbols have been 
used. Although the symbols have been changed each time there 
is a steady improvement, the changes being for four subjects 62 
to 52, 95 to 85, 71.5 to 58, 62 to 52, and 65 to 56. The major 
part of this gain could not have been due to merely getting used 
to the machine or the general features of the experiments, for the 
fourth subject was already used to these and still gained about 
nine tenths as much as the other three. 

The other experiment " consisted in taking daily records, for 
twenty days, by means of a stop watch, of the time required to 
repeat the alphabet from memory. Each day's experiment was as 
follows: First, the alphabet was repeated as rapidly as possible 
forward; secondly, the letter n was intercepted between each of 
the letters; thirdly, the alphabet was repeated as rapidly as pos- 
sible backward; and lastly, the alphabet was repeated backward 
intercepting n between each of the letters. At the end of twenty 
practices in each order the subject repeated the alphabet, first, for- 
ward, intercepting, instead of n^ the letter x and repeating three 
times; secondly, intercepting r and repeating three times; then 
lastly, repeating backward, and in like manner intercepting x and 
r and repeating three times." 

How far now did the training with the training series {ABC, 
AnBnCn, ZYX, ZnYnXn) help the ability in the tested series 
{AxBxCx, ArBrCr and ZxYxXx). There was improvement in 
the tested series, the effect of the twenty days' training with the 
training series being to put the abilities in the tested series as 
far ahead as three days of the direct training would have done. 



THE INFLUENCE OF SPECIAL TRAINING 93 

In botli of these experiments as in the others quoted the influence 
of training is measured within a very narrow field. 

On the whole what knowledge we do have of the actual influence 
of improvement of one function upon the efficiency of others har- 
monizes with the facts concerning the relationships between mental 
traits and makes it imperative that the present conceptions of 
the disciplinary effect of environmental agencies be subjected to a 
new critique on the basis of actual evidence. They surely over- 
estimate its amount. 

Their error is due in part to the fallacy of selection empha- 
sized in ^Chapter IX. Since those who succeed in the study of 
Latin are better in general discrimination and judgment than 
those who fail, we conclude that learning Latin vastly improves 
general discrimination and judgment. Since those who succeed 
in science are more efficient observers and reasoners about con- 
crete things than those who fail, we conclude that science is 
the mother of general observation and concrete inference. 

Another fallacy, that of attributing to the disciplinary effect of 
studies and occupations what is really due to mere inner growth 
or maturity, contributes its share. Boys and girls become more 
efficient in general discrimination, attention, self control, etc. At 
the same time they have been undergoing these special disciplines. 
It suits the vanity of educational theory to fancy that the changes 
are wholly due to the discipline. But it is almost certain that 
maturity alone would cause a fair gain in efficiency. 

Still a third fallacy, that of judging others by ourselves, has 
helped to blind educational theorists to the real state of affairs. 
They themselves are likely to be gifted men who could as boys 
and girls readily acquire and apply general ideas and habits. 
They fail to realize the state of mind of those to whom every task 
is a concrete performance to be done blindly, unproductive of 
any tendencies outside its own sphere. They mistake their own 
aptitudes at extracting general value from special disciplines for 
a general trait in human nature. 



CHAPTEK IX. 

THE INFLUENCE OF SELECTION. 

At the outset of our study of the influence of the environment 
was noted the common confusion of causes which train with causes 
which select. 

The recognition of the fact that environmental agencies not 
only alter those whom they affect but also select those whom they 
shall affect is of importance aside from the prevention of radically 
false conclusions. For their selective action is itself of no small 
consequence. If doctors of philosophy are superior teachers, presi- 
dents of colleges will not stop to inquire whether they were so by 
nature or by training. If high school graduates make superior 
clerks, business men will care little whether they were so by 
general wits and ambition or by virtue of the doses of algebra, 
Latin, etc., that they have taken. 

All environmental agencies and especially our educational 
agencies are a great system of means not only of making men 
good and intelligent and efficient, but also of picking out and 
labeling those who for any reason are good and intelligent and 
efficient. In the latter case they may be said to improve not the 
production, but the distribution of mental and moral wealth. 
They help to put the right men in the right places. They help 
the individual somewhat in so far as they advertise his true make- 
up and they help society in general tremendously by providing it 
not with better men, but with the knowledge of which men are 
good. In estimating the value of any educational system this 
selective function should never be disregarded. 

To have gone to school at all means not only that you have 
perhaps learned to read and write but also that you were not an 
invalid, idiot or runaway. To have progressed half way through 
the graded schools means not only that you have learned some- 
what but also that you were not one of the 10 or 20 per cent,* 
who by lack of means or ambition or health or mental ability 

* These figures are true for large cities. 

94 



THE INFLUENCE OF SELECTION 95 

have been eliminated from the school system. To have graduated 
from a high school means that yon are one of a very small per- 
centage of the group who entered school with you, a percentage 
picked for survival not by chance, surely. And so on with col- 
leges and professional schools. 

In the case of the cities of Boston, Chicago and St. Louis 
the amount of the elimination is that given in table IX,* which 
gives the number of children in each grade above the first in 
percentages of the number in the second grade. "" By the last 
v" year of the high school course 97 per cent, of the original group 

have been eliminated. Of these not more than 17 per cent, have 
died; the remaining 80 per cent, are dead only to the school sys- 
tem. 

TABLE IX. 

Ipt 2d 3d 4th 
2d 3d 4th 5th 6th 7th 8th H.S. H.S. H.S. HS. 

St. Louis 100 93 83 50 29 21 14 7 4 3 2 

Chicago 100 91 78 71 52 37 26 12 7 5 3 

Boston 100 97 91 85 74 59 44 25 15 10 4 

A college degree means literally that a man is the one man out 
of about 200 who has survived in the educational struggle. The 
important question here and at all stages is, " Which man is he ? 
What are the traits of personality or circumstances that ensure 
survival ?" 

That is the efficient school system in which survival is grade by 
grade the portion of those most fit to profit by the future training 
and to use well the distinction given them by the fact of that 
training. Too often however poverty is the eliminating force. 
And within the schools themselves the selection has been confined 
too narrowly to a basis of ability in abstract and symbolic studies 
such as mathematics, languages and pure science. The boy des- 
tined to efficiency in affairs, in applied science and technical 
industries, in the organization of manufacturing and commerce, has 
been eliminated from the system because he was not fit for sur- 
vival in it, though he was in every way one of the most fit for 
extended training. 

It is common to bewail the elimination of so many from school 
life and to rejoice at any numerical increase in the proportion 

* This table is taken from the excellent study of this question by Pro- 
fessor C. M. Woodward in the 1899-1900 report of the U. S. Commissioner 
of Education, Vol. II. 



96 EDUCATIONAL PSYCHOLOGY 

of children at any age who are under school influences. These 
opinions are probably justifiable, but the more important cause 
for regret or satisfaction lies, not in the quantity of those who 
continue school work, but in their quality. ' Out of a thousand 
six-year-olds there are a score whose higher education is of more 
value to the community than that of a hundred of their fellows. 

It is also an American habit to clamor about equality of oppor- 
tunity as the prime virtue of a school system. Equality at the 
start there should be, but the higher opportunities like the higher 
distinctions should be, as they always have been, earned. The 
schools always have and always will work to create a caste, to 
emphasize inequalities. Our care should be that they emphasize 
inequalities, not of adventitious circumstances, but of intellect, 
energy, idealism and achievement. 

Just how the educational systems of the United States do 
select individuals for different forms of training is a question the 
importance of which is in inverse ratio to the amount of our 
knowledge about it. We have here and there a measurement more 
or less precise. The small number of institutions for the training 
of the feeble-minded shows that the great majority of these are alto- 
gether eliminated from systematic education. Woodward, in the 
report quoted, demonstrates that the pupils who in the middle 
grammar grades are the older tend to be more frequently elim- 
inated. Thomas* found the high schools to select the younger 
and the higher ranking pupils, though in the schools studied only 
to a slight extent. They obviously select also those of relatively 
superior social position. They select from the general popu- 
lation more girls than boys. The scientific and modern lan- 
guage courses in colleges have far too often selected boys for 
their inability to pass the entrance examinations or do the work 
of the classical course. The theological schools select, by a pecul- 
iarly unfortunate custom, those young men who are attracted by 
free lodging and other gratuities. In general merit is chosen, but 
the student of education who shall discover the precise nature of 
the selective influence of American education will I fear convict 
us in some instances of a folly equal to that of the nations who 
eliminated their choicest stock by the monastery and the battle- 
field. 

* In an unpublished study made at Teachers College in 1903. 



CHAPTER X. 

CHANGES IN MENTAL TEAITS WITH AGE. 

Some of the best known and most commended studies in edu- 
cational psychology deal with the differences in mental traits 
between children of different ages. The most extensive and also 
the most painstaking study of this sort is Dr. Gilbert's " Re- 
searches on the Physical and Mental Development of School 
Children." * A fairly careful examination of its method and 
results will be our best introduction to the general problems of 
the chapter. 

Dr. Gilbert made a number of measurements of both physical 
and mental traits in boys and girls from six to seventeen years 
old. The mental traits were: 

1. Delicacy of discrimination of weight. (Ten weights iden- 
tical in shape and size but weighing 84 grams, 86 grams, etc., 
were set before a child and he was asked to sort out all those 
which seemed to him to be of exactly the same weight as the 
82-gram one (which was marked by a white dot). Delicacy of 
discrimination is then measured inversely by the difference in 
weight of the weights thought to be identical.) 

2. Delicacy of discrimination of color. (A series of reds 
varying progressively in darkness were used as the weights were 
in 1.) 

3. Force of suggestion. (Measured by the amount a child 
overestimated a weight small in size compared with the same 
weight made much larger.) 

4. Reaction time. (Measured by the time taken to see a sig- 
nal and react by pressing down a key.) 

5. Reaction with discrimination and choice. (Measured by 
the time taken to see that the signal was blue and not red and to 
react by pressing down a key.) 

6. Time memory. (The child was told to listen to a certain 
continuous sound to see how long it lasted and, the sound being 

* Studies from the Yale Psychological Laboratory, Vol. II. 

97 



98 EDUCATIONAL PSYCHOLOGY 

again made, to give a signal when he thought it had continued 
as long as before. The length used was two seconds.) 







TABLE X. 




._ 






Muscle-Sense, 






Age. 
6 


D 

14.8 


MV 
5.2 


B 
13.0 


G 

16.8 


7 


13.6 


4.4 


13.2 


13.2 


8 


11.4 


4.6 


12.2 


11.0 


9 


10.0 


4.4 


10.2 


10.0 


10 


8.8 


4.4 


8.6 


9.2 


11 


8.6 


3.8 


10.2 


7.6 


12 


7.2 


3.0 


7.6 


7.6 


13 


5.4 


3.0 


6.0 


5.6 


14 


5.6 


3.0 


5.2 


7.2 


15 


6.8 


2.2 


6.2 


7.2 


16 


6.6 


2.4 


6.0 


6.8 


17 


5.8 


2.6 


6.0 


6.4 


'> 


Sensitiveness to Coloe-diffeeences. 




Age. 
6 


J) 
9.6 


MV 
1.8 


B 

8.3 


G 

9.6 


7 


9.0 


2.1 


8.3 


9.6 


8 


8.3 


2.3 


9.6 


7.0 


9 


6.3 


2.2 


6.1 


6.6 


10 


5.4 


1.9 


6.0 


5.2 


11 


5.4 


1.7 


6.0 


4.9 


12 


5.1 


1.5 


4.8 


5.1 


13 


4.6 


1.7 


5.2 


4.1 


14 


4.7 


1.4 


4.8 


4.6 


15 


4.4 


1.1 


4.1 


4.6 


16 


4.3 


1.3 


4.3 


4.0 


17 


3.9 


1.4 


4.0 


4.9 




FoECE OF Suggestion. 




Age. 
6 


42.0 


MV 
17.0 


B 
43.5 


G 

42.5 


7 


45.0 


15.5 


43.5 


43.5 


8 


47.5 


13.5 


45.0 


49.5 


9 


50.0 


10.5 


50.0 


49.5 


10 


43.5 


12.5 


40.0 


44.0 


11 


40.0 


11.5 


38.5 


40.0 


12 


40.5 


9.0 


38.0 


41.0 


13 


38.0 


9.0 


37.0 


38.0 


14 


34.5 


9.5 


31.0 


33.5 


15 


35.0 


10.5 


33.0 


38.0 


16 


34.5 


10.0 


32.0 


38.5 


17 


27.0 


12.0 


25.0 


31.0 



CHANGES IN MENTAL TRAITS WITH AGE 99 

Voluntary Motob Ability. 



Age. 


r 


MV 


B 


MV 


O 


MV 


6 


20.8 


2.4 


21.0 


2.5 


19.7 


2.5 


7 


22.5 


2.9 


22.8 


2.7 


21.2 


2.5 


8 


24.4 


2.9 


24.9 


3.4 


23.9 


2.2 


9 


25.4 


2.5 


25.8 


2.5 


25.0 


2.9 


10 


27.0 


2.8 


27.7 


2.6 


26.9 


2.8 


11 


29.0 


3.3 


29.7 


3.2 


27.8 


3.0 


12 


29.9 


3.3 


30.3 


3.1 


29.6 


3.0 


13 


28.9 


2.8 


29.8 


3.0 


28.1 


3.3 


14 


30.0 


3.6 


31.2 


3.2 


28.0 


3.4 


15 


31.1 


3.0 


31.3 


2.6 


29.8 


3.2 


16 


32.1 


3.3 


33.0 


3.0 


31.8 


3.4 


17 


33.8 


2.9 


35.0 
Fatigiie. 


2.4 


31.5 


2.3 


Age. 


F 


MV 


B 


MV 


O 


MV" 


6 


21.4 


8.1 


22.8 


9.4 


21.3 


7.0 


7 


21.0 


8.9 


22.5 


9.7 


20.2 


6.7 


8 


24.0 


7.3 


24.7 


8.3 


23.3 


7.1 


9 


21.0 


7.1 


22.5 


6.7 


20.7 


7.8 


10 


22.0 


7.5 


22.7 


7.8 


19.0 


7.1 


11 


20.0 


6.2 


20.3 


6.5 


18.0 


5.5 


12 


16.0 


6.3 


18.0 


6.0 


14.0 


6.7 


13 


14.5 


6.4 


15.8 


6.7 


14.7 


5.8 


14 


14.0 


6.5 


17.8 


6.2 


12.0 


6.1 


15 


12.7 


5.8 


13.8 


4.9 


11.5 


5.7 



16 14.7 5.2 15.3 4.6 11.7 5.6 

17 13.8 5.3 14.5 6.3 13.5 4.3 

Reaction-Time. 



Age. 


Ta 


Tp 


MV 


B 


MV 


O 


MV" 


6 


31.7 


29.5 


5.0 


28.2 


4.6 


29.5 


5.4 


7 


30.9 


29.2 


5.5 


26.7 


4.6 


31.5 


5.2 


8 


28.7 


26.2 


3.9 


24.5 


3.9 


26.0 


3.1 


9 


26.9 


25.0 


4.1 


24.3 


5.4 


25.5 


4.9 


10 


23.3 


21.5 


3.6 


21.0 


2.6 


22.5 


4.3 


11 


21.0 


19.5 


3.4 


18.5 


3.1 


20.6 


3.4 


12 


20.7 


18.7 


3.1 


17.8 


2.7 


19.8 


3.5 


13 


20.5 


18.7 


3.0 


17.8 


2.9 


20.5 


3.5 


14 


19.1 


18.0 


2.9 


18.0 


3.0 


18.7 


3.0 


15 


18.4 


17.2 


2.7 


1G.7 


2.3 


18.9 


2.7 


16 


17.0 


15.5 


2.3 


14.7 


1.6 


17.2 


2.6 


1.7 _ 


f r47.0 


15.5 


3.3 


14.7 


1.9 


16.3 


2.6 



100 EDUCATIONAL PSYCHOLOGY 

Reaction with Disceimination and Choice. 



Age. 


Ta 


Tp 


MV 


B 


MV 


G 


MV 


6 


55.8 


52.5 


6.0 


53.5 


5.3 


51.0 


6.5 


7 


54.1 


53.0 


8.1 


49.0 


8.8 


52.8 


9.4 


8 


48.8 


47.8 


6.5 


48.0 


5.7 


47.5 


5.5 


9 


47.5 


45.0 


6.8 


44.5 


6.3 


46.0 


7.2 


10 


42.2 


41.0 


4.9 


40.0 


4.9 


41.5 


4.5 


11 


40.5 


38.5 


5.8 


38.7 


5.8 


38.8 


5.7 


12 


38.9 


37.0 


5.5 


38.5 


6.0 


37.0 


4.9 


13 


39.9 


39.5 


5.8 


36.0 


5.1 


41.5 


5.5 


14 


36.3 


36.5 


4.9 


36.7 


4.5 


35.5 


5.4 


15 


34.8 


33.5 


4.9 


31.1 


5.5 


34.5 


3.8 


16 


34.0 


32.5 


4.3 


31.5 


3.9 


35.0 


3.9 


17 


32.1 


31.2 


4.0 

TlME- 


30.5 

MEMORY. 


3.5 


31.5 


4.4 


Age. 


Ea 


Ep 


MV 


B 


MV 


G 


MV 


6 


56.7 


62.0 


23.4 


56.5 


25.1 


67.0 


23.2 


7 


59.6 


66.5 


20.2 


63.5 


20.6 


68.5 


20.4 


8 


52.7 


54.3 


22.8 


48.5 


22.3 


57.0 


22.3 


9 


56.2 


60.0 


23.5 


47.5 


22.4 


73.5 


19.3 


10 


48.9 


48.5 


18.1 


48.5 


21.8 


46.5 


15.8 


11 


44.2 


41.0 


18.2 


40.5 


16.6 


41.0 


20.2 


12 


41.6 


36.8 


21.3 


35.8 


21.8 


37.5 


18.7 


13 


36.3 


33.0 


21.4 


24.5 


22.0 


36.0 


19.5 


14 


35.9 


30.0 


16.1 


31.5 


14.2 


31.0 


17.8 


15 


37.6 


38.0 


19.4 


34.5 


15.3 


39.0 


21.9 


16 


41.6 


44.0 


16.7 


38.0 


16.5 


49.0 


14.0 


17 


39.9 


35.5 


15.8 


34.0 


13.8 


40.0 


17.8 



The essential results of Dr. Gilbert's study are given in table 
X.* These tell us with fair accuracy the median ability for 
every such group as nine-year-old girls or thirteen-year-old boys, 
and the variability of every such group except in the first three 
measurements. In these the variability is given only for boys and 
girls combined. 

Just what do these median abilities mean ? Just what do the 
differences between those for six and seven, seven and eight, etc., 
tell us about the development of mental traits in life ? Just what 
do we learn about human nature from these comparisons of the 
capacities of children of different ages ? 

It is clear that an alteration in any mental trait in any indi- 
vidual with age might be due to the mere maturing of some 
characteristic of original nature or might be the creation of some 

* Quoted from Dr. Gilbert's paper, but with some rearrangement. 



CHANGES IN MENTAL TRAITS WITH AGE 101 

environmental force. The educational inferences would be ex- 
actly opposite in the two cases. In the former we should say: 
This change comes as a gift from nature which we may not be 
able to refuse without damaging general growth. It is given 
as the partial basis and starting point for education. We do not 
have to try to get it. In the latter case we should say: This 
change comes as the earnings of training. It is a product of 
education. With a different training it might be absent. We 
may lack or possess it as we choose. 

Moreover in the case of many measurements of mental traits, 
for instance those quoted, the change due to an individual's age 
would be possibly due not only to the maturing of the trait or 
the influence of training upon it, but also to the influence of both 
maturity and training upon the ability to understand and the wish 
to follow instructions and the ambition to do well in tests. This 
complex of traits I shall call general ability in tests. It is even 
conceivable that the last factor was the sole cause of all the 
changes quoted above. 

Mere knowledge of changes of mental traits with age without 
knowledge of how their causation is distributed amongst these 
three factors can not guide us in the development of the trait. 
For instance, twelve-year-olds do better than eleven-year-olds in 
addition. Shall we conclude that age causes the difference and 
that practice in addition between those dates is a waste of time, 
or that training does it and that if before six we should give as 
much training as we now do before twelve, six-year-olds would 
then do as well as twelve-year-olds now ? Such knowledge does 
inform us about what abilities to expect at different ages under 
the conditions of birth and training of those measured and thus 
may be of practical service in grading children with sim- 
ilar training, deciding whether they are getting on well in tlieir 
education, and suiting a curriculum to their capacities. It also 
allows justifiable comparisons within the tests, such as of the 
sexes or of the amount of change at various stages in life. 

So far upon the supposition that by changes in mental traits 
with age we mean changes in individuals measured by measur- 
ing the individitals at different ages. The average change would 
then be the average of the changes of nil the individiinls studied. 



102 EDUCATIONAL PSYCHOLOGY 

But in the quotations given the diiference between the figures for 
say ten and eleven years is not the average of the changes of all the 
individuals studied and need not in any real way represent them. 

For (1) the difference between the average of a group at 
ten and of the same group at eleven years does not describe the 
real individual changes; and (2) when we measure ten and 
eleven-year-olds as we find them in school or elsewhere we can 
not be sure that the eleven-year olds represent what the ten-year- 
olds will become. 

The first point will be made clear by the following illustra- 
tion. Suppose that eighteen boys showed at the age of ten and 
a half years the abilities in some mental trait denoted by the 
measures in the first column and made the gains during the next 
year shown by the figures in the second column, their consequent 
records at eleven and a half years being given in the third col- 
umn. (Case 1.) 





Case 1. 






Case 2. 




AbUityatlO>i. 


Change. 


Ability at 11^. 


Ability at 10>^. 


Change. 


Ability at ll>^. 


2 


5 


7 


2 





2 


2 


5 


7 


2 





2 


3 


4 


7 


3 


1 


4 


4 


3 


7 


4 





4 


4 


4 


8 


4 


1 


5 


5 


4 


9 


5 


3 


8 


5 . 


1 


6 


5 


1 


6 


6 


3 


9 


6 


1 


7 


6 


3 


9 


6 


1 


7 


6 


1 


7 


6 


3 


9 


6 


1 


7 


6 


3 


9 


7 


1 


8 


7 


1 


8 


7 


3 


10 


7 


4 


11 


7 


1 


8 


7 


4 


11 


8 





8 


8 


3 


11 


9 


1 


10 


9 


4 


13 


9 





9 


9 


5 


14 


11 





11 


11 


5 


16 



Avg. 5.94 2.22 8.16 Avg. 5.94 2.22 8.16 

If instead of this complete record we had simply the figures : 
10^/2 years, Av. 5.94; IIV2 years, Av. 8.16; Change in average 
ability, 2.22, we should lack the essential features of our fact; 
viz., (1) the variability of the changes and (2) the antagonism 



CHANGES IN MENTAL TRAITS WITH AOE 103 

between ability at ten and a half years and growth during the 
next year. There is an almost inevitable tendency when a single 
figure is given to represent change to fancy that all children show 
exactly or nearly that amount of change. This is of course never 
true. Rate of change as well as absolute ability is variable. 
And it is precisely in relating the different degrees of progress 
found in individuals with their original capacities and individual 
circumstances, that educational insight will accrue. The real in- 
dividual changes may often prove to be a partial function of the 
amount of ability already acquired, as in our illustration. The 
mere change in average ability given above could have come as 
well from a condition, shown in Case 2, just opposite in this re- 
spect to that of Case 1. 

Here the better a boy is at ten and a half years the more he 
gains, whereas before the better he was the less he gained. Case 
2 would, I venture to prophesy, be the fact in the progress with 
age of real mental efficiency, while with physical growth from 
thirteen to eighteen we should have something like Case 1, the 
children who had matured early and so attained high stations in 
stature growing little, while those who matured slowly would keep 
on growing at a fair rate. In brief the growth of averages does 
not accurately describe and may positively misrepresent the real 
growth of the individuals in the group. 

Our second point was that the eleven-year-olds tested need not 
represent what the ten-year-olds would become. The average 
changes stated in the quotations at the beginning of this chapter 
were obtained from facts like the following: Ten-year-olds A, B, C, 
D, E, F, G, H, etc., give an average x; eleven-year-olds L, M, Nj 0, 
P, etc., give an average y. The change in average ability is y — x. 
IsTow the individuals of the two groups not being identical the 
chance is given for the fallacy of selection to run riot. The 
eleven-twelve-year-olds certainly represent only those ten-eleven 
year-olds who will live; in any test given in schools they repre- 
sent only the ten-eleven-year-olds who will eontimio in that type 
of school. JSTow if one measures a mental trait in grammar 
school children from the third through the seventh year of school 
life he gets for different ages something like the following fig- 



104 EDUCATIONAL PSYCHOLOGY 

ures:* Twelve years, 301; thirteen years, 256; fourteen years, 
198 ; fifteen years, 99. 

ITobody can imagine that the fifteen-year-olds here would give 
anything like a fair sampling of what the twelve-year-olds would 
become. The brightest twelve-year-olds pass out of the grammar 
school before they are fifteen. Some mental defectives leave for 
special institutions. Some moral defectives leave for reform 
schools or the free life of thievery and trampdom. Some chil- 
dren of very poor parents go to work. If we fill up our quota 
of fifteen-year-olds by adding 150 to 200 from the high schools 
we jump from the frying pan into the fire, for they are a selec- 
tion of the brighter, the more ambitious, those whose parents are 
fairly well off financially and are intellectually inclined. The 
opposite action of selection holds of course for five and six-year- 
olds taken in the first year of school life. 

I conclude, therefore, that the progress of mental traits with 
age has not been and can not be measured by such studies as those 
quoted. To measure it we must repeat measurements upon the 
same individuals and for all purposes of inference preserve intact 
the total fact of all the individual changes, measured in accordance 
with the statements about measurements of mental traits in a 
group of individuals made in Chapter 11. 

It is doubtful how far we know anything about the changes 
of mental traits with age; it is certain that from the probable 
changes which can be inferred from the studies made, the part 
caused by mere maturity has not been analyzed out. How inse- 
cure then must be any statements about the different rates of 
maturing for different functions, about general fluctuations in the 
rate of growth at different years, about sex differences in mental 
growth, or about the relation of bodily and mental growth. The 
plain and direct answers which repeated measurements properly 
handled would give are entirely lacking. Arguments there are 
from the observed facts, but they are so intricate and unfinished 
that it is a question whether it is not wiser to simply state the 
questions as problems to be solved. Indeed I shall do little more 
than that. 

* Obtained from two public schools in New York City. 



CHANGES ly MENTAL TRAITS WITH AGE 105 

1. Tlie Specialization of Crroivth with Age. 

"We may best take up this question separately in the case: 
(1) Of powers or capacities such as delicacy of sense discrimina- 
tion, different sorts of memories, the perceptive functions ; ( 2 ) of 
intellectual and emotional propensities, such as fits of rage, liking 
for puzzles, interest in science; (3) of habits, such as truancy, 
gambling, biting the nails, business industry, sleeping after din- 
ner; (4) of knowledge, e. g., of addition or spelling, of Latin 
or anatomy, of how to study. 

Of course these divisions all shade into each of the others, 
but, understanding always that the divisions are to some extent 
arbitrary, we shall gain clearness by their aid. 

1. Powers and Capacities. 

1. It is a favorite dictum of popular pedagogy that the mental 
powers ripen in a serial order, that each has its nascent period 




fig. H-a 



B. C. 



Fig. 40. 

when it gains rapidly, holds the stage for a while and then sinks 
back into relative stagnation while some other waxes, leads and 
then in its turn passes. 

The examination of the facts, however, shows no such antag- 
onism between the rate of growth of one function and that of the 
rest. On the contrary when we find rapid growth in delicacy of 
discrimination we find it also in the control of the higher powers, 
in accuracy of associations and in efficiency of memory and all 
the rest. General observation gives many competent students the 
opinion that facility in mere verbal memory does not increase 
after the age of ten or thereabouts, but the numerous systematic 
studies that have been made agree in finding a continuous im- 
provement. 



106 EDUCATIONAL PSYCHOLOGY 

The other extreme view, that the mind grows as an absolute 
unit, all powers progressing at the same rate, is equally unfounded. 
There are differences in the rates of change of different functions, 
which would surely appear in the results of repeated measure- 
ments as well as in the figures at hand. 

There is community of growth in functions, but there is also 
disparity. The question is not of the existence of these facts 
but of their amount. If we represent the changes in a power 
with age by the slope of a line then the facts will not be those 
of -S or C in figure 40, but something like those of A, though the 
exact slopes in A are not known. 

2. Intellectual and Emotional Propensities. 

These are specialized in growth in so far as they are due to 
instinctive tendencies, which are characterized in many cases by 
a sudden appearance and quick rise to a high intensity from 
which they may even fall off if they do not bring a sufficient in- 
crement of satisfaction to confirm them as habits. For instance, 
the zeal for physical combat evidently has its birthday in boy- 
hood and commonly dies long before old age. 

Any single account of the manner of specialization of growth 
of these propensities is however an impossibility, for their prog- 
ress depends little on any universal development of mental struc- 
ture from within and much upon physical and human surround- 
ings and specific training. Some octogenarians like to fight, some 
boys to sleep after dinner. Some races never lose the roving in- 
stinct that we Anglo-Saxons rarely see after boyhood. Inner na- 
ture has a large share in making certain instincts appear at certain 
epochs in development and last for certain lengths of time, but their 
future courses are unpredictable save by a complete knowledge 
of the environmental conditions of the individual throughout life. 
Their very appearances too, we must remember, may be hastened 
or delayed or modified in their manifestations by outer circum- 
stances. 

3. Hahits. 

These are obviously specialized in all sorts of ways for the 
same reasons as were given in the case of 2. 



CHANGES IN MENTAL TRAITS WITH AGE 107 

4. Knowledge. 

Mere age has almost nothing to do directly with the growth 
of knowledge, except that the material for knowledge, feelings of 
' things ' and images, does not appear till toward the end of the 
first year of life and that in the degenerative processes of old age 
knowledge often decreases. Indirectly age furnishes time as one 
condition of the increase in knowledge, a variety of instinctive 
feelings and acts as another, changes in capacities and powers as a 
third and new features of the environment as a fourth condition of 
changes in both the quantity and quality of knowledge. 

On the whole the different systems or masses of knowledge go 
each its own way in development depending on the special nurture 
they receive. Their rates of progress are necessarily alike only 
to the slight extent of their dependence upon the community of 
maturity of capacities and powers. 

Fluctuations in Mental Growth. 

If one picks his way through the facts without being misled 
by the fallacy of selection into attributing a change in average 
ability of age groups to age when it is really probably due to the 
elimination of certain individuals, his conclusion must certainly 
be that mental growth is very steady. 

In figures 41 and 42 are given the average abilities for dif- 
ferent ages of such mental traits as have been measured in age 
groups from eight to fifteen with at least forty individuals in each 
group. 

If we consider these in the light of the probable action of 
selection, we find no evidence that would justify us in asserting 
of any one epoch between eight and sixteen that it was the period 
of most rapid mental growth, or of any other epoch that it was 
the period of least rapid growth, though I venture the prediction 
that more complete and accurate knowledge will justify a common 
opinion by showing a rapid mental growth following upon the 
rapid physical growth at the time of puberty. At present, how- 
ever, there is insufficient evidence. There is certainly no very 
great fluctuation, for such would appear clearly even in the few 
and confused statistics tlint we do possess. 



108 



EDUCATIONAL PSYCHOLOGY 



The reader must not forget that fluctuations in the growth of 
individuals are to a large extent independent of the fluctuations 

BOYS. GIR.LS. 

o..o,t V5 IS 10.5 IIS I2S lif Hr US- 95 IS los tu lis ijs fv;} |{^ 









LtnjtK. 




X T«t. 
VfT«t. 



Ttst. 



BOYS. GIRLS. 

«^ ?/ /flr ";/.E /2S m /w IS! is 9S los lis lis m «r iff- 




R^iUtrntt To 



Worii. 






Rofe. o\Movn.ittitI. 



Figs. 41 and 42. An upward slope of the line means improvement. The degree of slant 
represents ttie amount of improvement, These amounts are in every case measured in terms 
of the variability of twelve year olds as a unit. The different tests are thus rendered as 
nearly commensurate as may be. The top left hand figure would thus read : At 8.5 years the 
delicacy of discrimination of weight is 1.53 below that of 12.5 year olds, l.CO equalling the 
mean variation of 12 year olds ; at 9.5 years it is .87 below that of 12.5 year olds; at 10.5, .33 
below ; at 11.5, .87 below ; at 13.5, .53 above ; at 14.5, .80 above ; at 15.5, .47 above. The progress 
is thus : 8.5 to 9.5, a gain of .66 ; 9.5 to 10.5, a gain of .54, etc. 

of the averages, A might go up and dov^n and B at the same 
period go down and up with no effect upon the average. How 



CHANGES IN MENTAL TRAITS WITH AGE 



109 



Sex Differences in Development. 

often and to what extent such individual fluctuations occur will 
be ascertained when repeated measurements of mental traits are 
taken over a number of .years. 

If we compare the progress for boys and girls shown in fig- 
ures 41 and 42, once more keeping in mind the changes that 
might be made by proper 
measures of growth, we find 
no clear and emphatic sex dif- 
ferences. FigTire 43, which | r- 
gives the averages for different i (' 
ages, in those functions where 
we have the least inadequate •^• 
information, also fails to show 
any difference of practical im- Y 

DOrtanCP fig. 43. Drawn in the same manner as 41 

jjv L<x uc. and 42, save that the continuous lines repre- 

sent the progress in the case of boys and 
the broken lines that in the case of girls. 




The Relationships between Physical and Mental Growth. 

These can not be profitably discussed until repeated measure- 
ments are at hand. The correlation between changes in physique 
and changes in mental traits in individuals and not between the 
average changes in groups is the measure we need. At present 
one can only guess at them. 

Lest the reader put undue emphasis upon these comments on 
the specialization of mental growth, its fluctuations, sex differ- 
ences and the connection between bodily and mental growth, I 
repeat again that the facts necessary to fully justify conclusions 
of any sort are still unknown. 



CHAPTER XI. 

SEX DIFFERENCES IN MENTAL TRAITS. 

The general practice of systematic and home education has 
been to treat boys and girls differently. Unreasoning tradition 
has for the most part been the basis of practice, but recently as 
the result of a growing tendency^ strongest in America, to elim- 
inate differences of training, there has been a conscious effort to 
attain a theoretical basis for both the old and the new practices. 
This effort has been guided more by hopes, fears and prejudices 
than by calm logic and pure scientific curiosity, and the litera- 
ture representing it is not of the most satisfying candor. 

By way of preface to our account of sex differences let us 
note first that their existence does not necessarily imply in any 
case the advisability of differences in school and home training, 
and per contra that even if the mental make-up of the sexes were 
identical it might still be wisest to educate them differently. It 
is true that a difference of two groups in a mental trait will theo- 
retically involve differences in treatment, but practical consid- 
erations apart from that of developing the highest efiiciency in that 
trait may outweigh the advantages of the differential treatment. 
For instance, consumptives theoretically need a different mode 
of life from people with healthy lungs, but it might in some cases 
be wiser to leave a consumptive to his ordinary habits rather than 
to cause in him consciousness of his disease and worry concern- 
ing it. On the other hand, two boys might be identical in mental 
structure, yet their education might best be quite different if we 
wished to make one of them a chemist and the other a psycholo- 
gist. 

Let us note in the second place that the existence of differ- 
ences need not imply the need of different training, because those 
very differences may have been due to the different training actu- 
ally received and might have never appeared had training been 
alike in the two classes. It is folly to argue from any mental 
condition in an individual or class without ascertaining whether 

110 



SEX DIFFERENCES IN MENTAL TRAITS 111 

it is due to original nature or to training. And tlie contents of 
this chapter should properly have appeared under the two sepa- 
rate headings of ' the mental traits due to the differences in the 
environments acting upon the two sexes ' and ' the mental in- 
heritance correlated with sex.' It is only because in most cases 
we are ignorant of the most important fact of all, the causation 
of the sex difference in question, that we are driven to the unsatis- 
factory method of describing sex differences and adding here and 
there what evidence we can about their causes. 

A further caution is necessary before this description and in- 
complete analysis begins. It is not to confuse differences in 
behavior, achievement and mental activities indirectly caused by 
physical traits with such differences directly caused by mental 
traits. Lack of muscular strength and the phenomena intimately 
associated with bearing children may serve as samples of such 
physical traits. Only 10 per 
cent, of women are stronger 
than the weakest 5 per cent, 
of men! Consequently even if 
women possessed mental capac- 
ities for business identical with ...••"-••.. 
those of men, they still would / \ T^g.fi-* 
not in active work do as much. / MEN \^ 

In the fourth place the f al- ,..'■-" /''b^'^-.] '"•-■ _ 

lacy of selection must not be for- j ^ <f lo n n n t^ '■^ " '^ " 
gotten in our comparisons of Fig- 4. 

men and women. Comparison 

will never be justifiable unless the men and women taken as samples 
are selected from the same sections of the two surfaces of fre- 
quency for the trait in question. We learn nothing but errors 
about men and women in general by naively comparing directly 
the two groups represented by A and B in figure 44. 

For instance, any inference from a comparison of young men 
and women in college or of working women with men in the same 
profession is untrustworthy. College women and college men are 
two classes selected by different agencies. For instance, of the 
children of fashionable people many girls go to academies to be 
adorned for life's leisure, while their brothers go to college. Again 




// 12. 13 ti IS" ic n If 



112 EDUCATIONAL PSYCHOLOGY 

the intellectual impulse is relatively a more powerful agent in 
sending girls to college, while convention and the demand for a 
pleasant social and athletic life act more powerfully on boys. 
In the case of an industry, say laundering, women are selected 
by relative ignorance, strength, widowhood, drunken husbands, 
etc., while the men are selected largely by Chinese birth. Let not 
the bizarre nature of this particular illustration blind us to the 
fact that women and men physicians, lawyers, stenographers, 
teachers or government clerks represent different samplings of 
the two sexes. It is possible theoretically to make a discount for 
the differential influence of selective agencies and thus permit a 
fair comparison, but actually such a procedure is well-nigh use- 
less. The advocate of male superiority in intellect might thus 
say that high school teaching selects from the higher ranks of 
female intellect and from mediocre ranks of men, yet men teachers 
of this species are brainier. But the major premises may be 
doubted. Perhaps relative poverty is the chief factor that selects 
women for high school teaching. 

As always, the safest comparison will be one of the two total 
distributions. If, however, the distributions are normal the cen- 
ter of gravity alone may be used and if we allow for differences 
in variability, the measures of any percentile grade. For obvi- 
ously if the two distributions are of equal variability the measure 
of the highest man or the seventh highest in a hundred or the 
twenty-fifth highest or the sixteenth from the lowest or any other 
will be as much above or below the measure of the woman holding 
a corresponding position among women as the average man is 
above or below the average woman. In many cases comparison 
of the upper limits in a trait is much more convenient than 
that of averages. We shall profit therefore from ascertaining 
whether or not the sexes are of equal variability. What the in- 
fluence upon comparison of .unequal variability would be need 
not concern us until we find it to be the fact. 

Besides its importance as a prerequisite to any comparison 
of the general amounts of a mental trait present in the two sexes, 
knowledge of their variability is intrinsically of importance. Let 
us suppose, for instance, that the average morality for men and 



SEX DIFFERENCES IN MENTAL TRAITS 113 

women is the same and call its amount m. Let us suppose that 
the standard deviation of men from m is .1 m and for women 
.3 m. Then all the men* will be between .7 m and 1.3 m^ the 
best man being not quite twice as good as the worst man. The 
limits for women however will be .1 m and 1.9 m, the best woman 
being nineteen times as good as the worst. ISTearly 16 per cent, 
of women will be better than the best man and nearly 16 per cent, 
worse than the worst man. Thus, though the average morality 
is the same, we have differences of tremendous practical moment. 
The great acts of honor, philanthropy, nobility and sacrifice 
would all be due to women. At the same time they would com- 
mit all the basest of crimes and iniquities. They would lead in 
all moral endeavor but would also fill the jails and dens of wick- 
edness, while the men would present lives of equable uninteresting 
mediocrity of both vice and virtue. If the reader will contem- 
plate the practical importance of a similar difference in the vari- 
ability of the sexes in intelligence, originality, musical talent, 
piety and other traits he will see that its measurement is in 
no wise an academic luxury or the perverse fad of theoretical 
statistics. 

In studying sex differences both in the amounts of mental 
traits and in their variabilities, it is important to treat different 
ages separately. For in the first place any sex difference that 
did exist would perhaps appear only after puberty and increase 
up to the time of physical maturity, and in the second place the 
meaning of sex differences for educational theory varies with the 
age when the difference exists. Differences in adults must be 
considered in connection with the question of different aims in 
the education of the two sexes, but may only indirectly recom- 
mend differences in the means and methods with children in the 
grammar school period. Differences in boys and girls will bear 
directly upon the practical questions of coeducation, curriculum, 
hours of attendance and methods of teaching. 

The Yariability of the Sexes in Mental Traits. 
It is a common belief that the male is the more variable. 
Karl Pearson has, to use his own words, ' laid the axe to the 

* More precisely 9,974 out of 10,000 of them. 



114 EDUCATIONAL PSYCHOLOGY 

root of this scientific superstition ' in the case of physical traits, 
but his measurements are of a narrow range and his opponents 
still find reasons for persisting in their view. 

In comparing the variabilities of the sexes we must of course 
make an allowance for differences in absolute ability. If the 
same law governed the variations in height of six-footers and five- 
footers the absolute variability of the former would still in figures 
be larger than that of the latter. The absolute variation in 
the length of the sermons, for instance, would be much greater than 
that in the length of the sentences of which they were composed, 
but really the latter are much more variable. We may make 
our allowance by taking the proportion of the average or median 
that the variability is. This figure is called the coefficient of 
variability. 

It is unfortunate that so little information is available for a 
study of sex differences in the variability of mental traits in the 
case of individuals over fifteen. Such statistics as I have been 
able to secure give measures in 26 objective tests, with from 100 
to 1500 individuals, and in 25 records of school marks with from 
60 to 1,000 individuals. 

The comparisons in the case of reaction time, reaction time 
with discrimination and choice and time memory are based on the 
measurements given by Gilbert (Yale Studies, Vol. II, 40-100). 
For the data in spelling, arithmetic and in the r-e and o-n tests 
I am indebted in part to Messrs. E. L. Earle, W. A. Eox and L. 
W. Cole. 

The nature of the material, which represents measurements 
taken by different individuals and often with only small groups, 
makes inferences from details unreliable. The data would be 
slightly more accurate if all records had been reduced to a com- 
mon month age at least, but this could not be done with the meas- 
urements taken by other observers than myself and would involve 
an amount of labor out of proportion to the increase in accuracy. 
The main facts that are relevant to our present purpose are as 
follows : 



SEX DIFFERENCES IN MENTAL TRAITS 115 

TABLE XI. 
Ratio of Femaxe to JIale Variability. 

By ages. 9 10 U 12 13 14 15 16 17 

A test 86 1.11 1.04 .94 1.08 1.03 1.07 

A-t test 91 1.05 1.05 1.07 1.35 1.07 .73 

Easy opposites test .97 .81 1.10 1.24 .89 1.15 

Word test 1.05 .91 .85 .87 

Memory (related words). .77 1.37 .93 .72 
Memory (unrelated 

words) 77 .46 .94 .66 .77 1.28 

Discrimination of length. .75 .80 .81 .98 1.04 .70 .78 
Simple and discriminative 

reaction time 98 1.21 .98 .93 1.00 1.11 .83 1.14 1.22 

Time memory 56 .75 1.21 .82 .85 1.27 1.26 .66 LOG 

■C Y 

General ratio. Average.. .92 1.025 .97 

Median .. .93 1.035 .95 

The chances are 1 to 1 that the true result will not vary from the one 
obtained by more than .023 (9-12 yrs.), .04 (13-14 yrs.), .055 (15 yrs.). 

By grades. 4 5 6 7 8 1st high. 

R-e and on tests 77 1.19 .97 .82 .85 

Spelling 55 .69 .55 .68 .08 

Addition 1.00 .91 1.06 .85 .97 

Multiplication .56 1.15 

In a number of tests (six in all) the ratio of first-year high school 
girls to boys in variability was .975. 

In tests in arithmetic (six in all) the ratio of high school girls to boys 
in variability was .96; in regents' examinations in Latin, English and in 
history, it was .96; in school marks in eight subjects, it was on the average .86. 

In college marks in fourteen different courses the ratios averaged .85. 

These facts make it extremely probable that, except in the two 
years nearest the age of puberty for girls, the male sex is slightly 
more variable. From the time of puberty for boys to maturity 
this difference seems to increase rapidly, though the records of 
marks which support this conclusion are not the best of evi- 
dence. The difference in variability is not sufficiently great 
to make any radical change in educational methods advisable, but 
does perhaps explain in part the general experience of teachers 
that the most striking cases of intellect, character and behavior 
are commonly boys. Tt also proves conclusions about the capaci- 
ties of the sexes in general based upon the comparison of the 
extremes in both cases to be certainly risky and probably false. 
For instance, suppose that we picked (Hil llu^ hundred most gifted 



116 



EDUCATIONAL PSYCHOLOGY 



intellects from a million men and a similar hundred from a mill- 
ion women. Even if in both sexes the average intellectual abil- 
ity was identical we should, if the variability of women was 95 
per cent, of that of men, probably find no woman of our hundred 
who was equal to any one of the hundred men. Conversely if 
we were arguing concerning the general moral superiority of 
women from a comparison of the frequencies of criminal offenses 

in the two sexes. 

Differences in Ability. 

The general facts which appear from such measurements of 
sex differences in mental abilities as I have been able to collect 

or make are given below. The 
material used in the comparison 
is essentially the same as was 
used in comparing the variabil- 
ities of the sexes. To make the 
measures comparable I have 
stated them in terms of the 
percentage of boys who reach or 
exceed the ability shovsm by 50 
per cent, of girls. If the sexes 
are equal then, the figure will 
be 50. If the figure is 99, it 



TiV^ 




Pig. 45 The dotted lines en close the means that all but One per cent. 

surfaces of distribution for boys and the con- J^ 

tinuous lines those for girls. 1 shows how 
very similar the abilities of the sexes are in a 
casewhere 60 per cent, of boys reach or exceed 
the median for girls, 2 shuws the facts when 
about 69 per cent, of boys reach or exceed the 
median for girls, 3 the facts when the percent- 
age is 84, and 4 when it is 100. 



of boys are better than the me- 
dian (practically the same will 
hold for the average) girl. Un- 
less the figure is under 25 or 
over 75 the difference does not amount to much practically. 
This may be seen clearly from the diagrams of figure 45, which 
show approximately the forms the distributions will take in the 
case of various differences. This method of stating differences 
has the advantage of showing the amount of resemblance at the 
same time as the amount of difference and of freeing figures 
from ambiguities due to differences in the scales of measurement 
or in the variabilities of the traits. Moreover from the extent 
to which the two groups coincide we can determine the practical 
importance of a differentiation of school work to meet the sex 
difference in ability. 



SEX DIFFERENCES IN MENTAL TRAITS 117 

TABLE XII. 

Sex Diffeuences in ABrLiTiEs. 
In the Case of Boys and Girls 8-14 Yeabs of Age. 

In delicacy of discrimination 56 % of boys who reach or exceed the 

ability reached or exceeded by 
50% of girls. 

In reaction time 57 % " " " 

In tests of the associative and con- 
ceptual processes, e. g., opposites 
test, alphabet test, addition, mul- 
tiplication, word test 48% " " " 

In the rate and accuracy of percep- 
tive processes 33 % " " " 

In temporary memory 40 % " " '* 

In spelling 33% " " " 

In resistance to the size weight illu- 
sion 55% 

In the Case of Boys and Giels 15, 16 and 17 Yeabs of Age ob of Gboxjps 
taken as Found in High Schools. 

In sense discrimination 60 % of boys who reach or exceed the 

ability reached or exceeded by 
50% of girls. 

In reaction time 76 % " " 

In tests of the associative and con- 
ceptual processes 50 % or > " " 

In English (regents' examinations 

and school marks) 41 % " " 

In mathematics (regents' examina- 
tions and school marks ) 57 % " " 

In Latin (regents' examinations and 
school marks) 57% 

In history (regents' examinations 

and school marks) 60% " " 

In the Case of College Students. 

In English about 35 % 

" mathematics about 45 % 

" history and economics about 56% 

" mental sciences about 50 % 

" modem languages about 40 % 

These figures are not to be taken without remembrance of tlie fact that 

in the colleges whence they came the selection of women is the narrower and 
probably the better. 

It is clear in the case of the mental traits that have been 
measured, (1) that the two sexes occupy almost the same stations, 
(2) that the greatest difference is the female superiority in the per- 
ceptual processes. 



118 EDUCATIONAL PSYCHOLOGY 

This difference accords well with the time-honored theory that 
in the perceptual and absorptive powers the female leads. The 
other half of the theory, that the male is the more aggressive 
and logical is not verified by our figures. It is unfortunate, as I 
suggested earlier in this chapter, that the measurements of in- 
dividuals over fifteen are so scanty and so confined to school 
abilities. 

The differences in ability, like those in variability, are not of 
sufficient amount to be important in arguments concerning dif- 
ferentiation of the curriculum or of methods of teaching in con- 
formity with sex differences. They may serve perhaps to make 
the expectations of teachers and superintendents concerning the 
accomplishments of pupils somewhat more rational. In strict 
justice, for instance, we should in school work, as in scientific 
investigations, assign any one marks in relation to the average 
:for his sex. And of course the figures have a great value as a 
Tebuke to those who indulge in wild speculations about this or 
that great difference between the capacities of boys and girls. 

We have now to turn from a careful and fairly satisfactory 
study of sex differences in a score or so of mental traits all of the 
type of intellectual capacities, to a looser discussion of the life of 
feeling, action and general achievement. Here j)recise measure- 
ments will be seldom at our service. 

The most striking difference in instinctive equipment con- 
sists in the strength of the fighting instinct in the male and of 
the nursing instinct in the female. No one will doubt that men 
are more possessed by the instinct to fight, to be the winner in 
games and serious contests, than are women; nor that women are 
more possessed than men by the instinct to nurse, to care for and 
fuss over others, to relieve, comfort and console. And probably 
no serious student of human nature will doubt that these are 
matters of original nature. The out and out physical fighting 
for the sake of combat is preeminently a male instinct and the 
resentment at mastery, the zeal to surpass and the general joy 
at activity in mental as well as physical matters seem to be closely 
correlated with it. It has been common to talk of women's 
*■ dependence.' This is, I am sure, only an awkward name for 
less resentment at mastery. The actual nursing of the young 



8EX DIFFERE'NCES IN MENTAL TRAITS 119 

seems likewise to involve equally unreasoning tendencies to pet, 
coddle, and ' do for ' others. The existence of these two in- 
stincts has been long recognized by literature and common knowl- 
edge but their importance in causing differences in the general 
activities of the sexes has not. The fighting instinct is in fact 
the cause of a very large amount of the world's intellectual en- 
deavor. The financier does not think for money nor the scientist 
for truth nor the theologian to save souls. Their intellectual 
efforts are aimed in great measure to outdo the other man, to sub- 
due nature, to conquer assent. The maternal instinct in its turn 
is the chief source of woman's superiorities in the moral life. 
The virtues in which she excels are not so much due to either any 
general moral superiority or any set of special moral talents as 
to her original impulses to relieve, comfort and console. 

Training undoubtedly accentuates these inborn differences 
since boys play more with boys and are trained more by men, the 
opposite holding with girls. A reversal of training by which 
girls would be surrounded by the social milieu now affecting boys 
would, as we often see in isolated cases, lessen the sex difference. 
But we may be sure that if we should keep the environment of 
boys and girls absolutely similar these instincts would produce 
sure and important differences between the mental and moral 
activities of boys and girls. 

Since these differences in instinctive equipment are true 
causes it seems wise not to invoke other less probable traits to 
account for any fact which these seem fairly adequate to explain. 
For instance, if the intellectual achievement of men was found 
to be superior to that of women we could explain it either by an 
actual difference in intellect or by the zeal and activity due to 
the fighting instinct. Our rule would be to exhaust first the in- 
fluence of the known physical differences and second the influence 
of the instinct in question. Only if these were inadequate should 
we resort to the hypothetical cause of differences in purely intel- 
lectual caliber. 

On the basis of the facts known a decade ago Ilavelock Ellis* 
chose as general sex differences the greater variability, affecta- 
bility and primitiveness of the female mind. The first point has 

* ' Man and Woman.' 



120 EDUCATIONAL PSYCHOLOGY 

been discussed fully. Bj affectability he means not only greater 
impressibility by and responsiveness to stimuli of all sorts, but 
also less inhibition of the emotions and other instinctive reac- 
tions. The fact seems indubitable though its exact amount can 
not be even roughly estimated. I^ot only the superiority in tests 
of perceptual power and the greater suggestibility which we have 
noted, but also the relative frequency of dreams, trance states and 
emotional outbreaks and the common differences between our treat- 
ment of the men and of the women with whom we are associated, 
witness to it. In his evidence for and discussions of the primi- 
tive nature of women Mr. Ellis seems to have physique in view 
primarily. How far women resemble uncivilized races and chil- 
dren in mental make-up is, to me at least, not at all clear. 

The same author emphasizes as so many others have done the 
fact of female dependence or lack of aggressiveness in intellect. 
The qualities that we call original, constructive, organizing and 
critical are ill defined and comparisons are hard to arrange be- 
cause men and women have devoted the active powers of the intel- 
lect to such different fields. Comparison of the most eminent 
representatives from both sexes is obviously unfair in so far as 
men are more variable. 

If we are to believe the novelists and playwrights women are 
more concerned with their own feelings and personalities than 
men, are emotionally more subjective. This is not inconsistent 
with the existence of greater sympathy of the motherly sort, nor 
with the possibly superior gifts of men in the examination and 
intellectual manipulation of subjective conditions. An interest- 
ing bit of evidence supports the conventional view of fiction. 
Many people carry on as a systematic day dream a continued story 
in which they figure and which possesses its interest from the 
chance it gives to think pleasantly of oneself. Three and a half 
times as many women as men do this (46.7 per cent, and 13.5 per 
cent.).* 

♦Mabel W. Learoyd, 'The Continued Story,' Am. J. of Psy., Vol. VII., 
pp. 86-90. 



CHAPTER XII. 



EXCEPTIONAL CHILDREN. 



Feom the discussion of the distribution of mental traits in 
Chapter III. it was evident that unless peculiar causative or selec- 
tive agencies are at work there will be a few individuals who will 
possess so little of any given capacity or quality as to be obviously 
' defectives ' in it, as well as a few who will possess so much 
as to be obviously ' prodigies.' There will be a larger number 
who will possess so little as to merit the popular term ' weak ' 
in color vision, memory, self-control, moral sense, general intelli- 
gence or whatever the trait may be. They again will be balanced 
by an approximately equal number of ' remarkable ' or ' excep- 
tionally gifted.' 

If the mental trait in question is the compound of many traits 
which we call intelligence we shall find at the lower end of the 
distribution curve children whom medical diagnosis would name 
idiots, and next them a number who would be termed imbeciles, 
and nearer still to the average the group to whom the name weak 
or feeble-minded would be applied. If the mental trait is the 
compound called ' morality ' the individuals at the low extreme 
will perhaps be diagnosed as cases of ' moral insanity ' or as 
' moral degenerates.' If the trait be more specific, for instance 
if it be ability to learn to spell, ability to learn to read, cruelty, 
musical ability, memory, visualizing power or what not, we shall 
find few if any special names for different degrees of its posses- 
sion, though there will as truly be defectives in respect to any 
such specific mental trait as in respect to general intelligence. 

The means which educational endeavor will use and the re- 
sults which may be expected from it will in the case of any indi- 
vidual depend upon his station in the trait in question. No one 
unless he were himself an ' idiot ' in the trait of common sense 
would train a genius and an idiot alike or expect them to develop 
alike. At present there is a widespread practice of providing 
separate treatment at home or in institutions for idiots and ini- 

121 



122 EDUCATIONAL rSYCHOLOGY 

beciles, thougli some are to be found in the common schools. And 
there is a growing demand for institutions and separate classes 
for the feeble-minded. I^^otable moral defectives are being cared 
for in separate classes in some cities. Thej also, when the parents 
are wealthy, find refuge in private schools of a certain type 
and in the somewhat mercenary ministrations of private tutors. 
The children exceptional in their great superiority to the average 
are not systematically given any special attention except here and 
there by systems of rapid promotion. Exceptionally high- or low- 
grade children in any single trait are unprovided for apart from 
the wisdom of parents or teachers. 

Tor the proper treatment of exceptional children we need 
knowledge of the exact distribution of all the mental traits which 
we desire to develop or abolish, of the causes which determine 
an individual's station in each, of the symptoms by which we may 
conveniently find out any one's station in each, and of the agen- 
cies, educational, hygienic and medicinal, which alleviate or in- 
tensify the different conditions. The last involves the study of 
the differential action of stimuli upon individuals of different 
stations. For instance the training of idiots should rest upon: 

1. A consideration of the distribution of intelligence which 
will tell us what the frequencies of different degrees of low mental 
capacity are. 

2. A study of the extent to which original nature decides an 
individual's station in intelligence and of the displacements of 
individuals from their original station to a lower station by acci- 
dent, disease, unwise training, etc. 

3. A study of the physical and mental symptoms which en- 
able us to measure a person as very, very low in intelligence. 

4. A study of the influences of climate, food, operative sur- 
gery, medicines, manual work, school work, good and bad ex- 
ample, etc., which make the mental condition better or worse. 

In the case of idiocy, imbecility and pronounced feebleness 
of mind, psychology, mental pathology and medicine could show 
a respectable array of facts for the student, though precise quan- 
titative studies fit to serve as models for study are lacking. We 
know at least roughly the frequency of intellects so defective as 
to disturb the home, resist school influence and excite popular 



EXCEPTIONAL CHILDREN 123 

pity or derision (about 1 in 500). We know that in all 
probability by original nature human beings are distributed 
according to a frequency curve with some elimination at the low 
end, and that one's ancestry decides one's position; that the ordi- 
nary circumstances of life in which people differ do not much 
alter one's position compared with his fellows, but that many 
special influences, e. g., brain injuries, hydrocephalus, cretinism, 
scarlet fever, etc., may displace a person to a lower station. Some 
of these influences probably act indifferently upon individuals of 
all original stations, so that so far as concerns them idiocy may 
be caused in one of the most intelligent ancestry. On the other 
hand many of these produce idiocy only upon the fertile soil of 
originally weak mental structure. As regards symptoms we are 
not so well off as we may hope to be in the future. Idiocy can 
not be recognized as early in life as it should be nor always dis- 
tinguished from mere backwardness, nor can its different degrees 
be measured with convenience or with precision. As regards 
treatment for amelioration we have a great amount of informa- 
tion, though not all of the best quality. 

But if we look for similar information concerning other men- 
tal defects we are doomed to disappointment. And exceptional 
children at the high end of the distribution curve have been so 
little studied that the very words exceptional and abnormal are 
commonly used to refer only to those exceptionally defective. A 
systematic treatment of the whole subject is thus out of the ques- 
tion and we must be content with (1) a series of rather disconnected 
and ill-proportioned comments representing the present state of 
knowledge and opinion on matters which concern educational 
theory and practice and (2) an outline which will suggest what 
we ought to know but do not. 

Exceptional Swperiority . 

The greater the superiority in any mental trait or combina- 
tion of traits the rarer it is. This decrease in frequency is 
roughly that of the normal frequency curve of Chapter 1 TT. 

Exceptional superiority almost certainly exists in the ease of 

every mental trait or combination of traits.* 

* Possible exceptions here and in the case of exceptional inferiority 
would be traits where over a certain amount, say x, or under a certain 



124 



EDUCATIONAL PSYCHOLOGY 



Some of the obvious and practically important cases are: 

Total intelligence. 

Mental balance. 

Efficiency or capability. 

Energy. 

Quickness of mental processes. 

Breadth of mental processes. 

Strength or intensity of mental processes. 

Abstract power. 

Permanence of memories. 

Mathematical ability. 

Musical ability. 

Ability in drawing or painting. 

Mechanical insight. 

Steadiness. 

Courage. 

Sociability. 

Affection. 

Enthusiasm. 

The list might of course be indefinitely prolonged. 
Causation. — The causation of exceptional superiority is orig- 
inal nature plus or minus a displacement, commonly slight, due 

to environmental influence. The 
environment may displace a per- 
son downwards to a great extent, 
but upwards much less easily. 
The forceps of the physician, 
the strain of disease, the shock 
of brain concussion, may reduce 
original superiority to pro- 
nounced defect; but medicine, 
favorable training and the im^ 
petus of zeal seldom elevate a 
mediocre person to top rank. In 
the case of the combination of 
gifts which we call intelligence 
they never do, for it is only by the concentration of much energy 
in a narrow line that an originally inferior person becomes 
superior. For him to do so in all lines is impossible. 

amount, say y, of a mental quality would prevent survival, while conditions 
just below X or just above y would be much more favorable. We should 
then have distributions like A, B or C in figure 46, according to whether the 
first or second or both of these hypotheses were the fact. 




Fig. 46. 



EXCEPTIONAL CHILDREN 125 

Diagnosis. — The symptoms of superiority in any trait are clear 
when the trait itself can be directly measured. It is easy to tell 
an exceptionally good speller in school or scientist in adult years 
or soldier in war or orator in the pulpit. But when we have to 
infer the future from present and past symptoms in young chil- 
dren or judge a general trait from a few particular manifesta- 
tions, our inferences lack surety and precision. Superior effi- 
ciency in life's work, for instance, is not at all clearly shown 
by superiority in school tasks; success in formal grammar is 
not clearly symptomatic of general abstract ability ; the best 
boy in a thousand in discriminating length may not turn out much 
if at all above the average in general keenness of sense discrimina- 
tion. When the relationships of a great many mental traits have 
been worked out in the way shown in Chapter IV., any one meas- 
urement will serve as a symptom to an extent now impossible. At 
present a wise rule is never to infer from a symptom any condi- 
tion which moderate effort will enable you to measure directly, 
and never to infer future conditions from present symptoms with- 
out continuing observations into the future and modifying your 
inference as they direct. 

Control. — The development in individuals of a trait in which 
they are exceptionally superior would undoubtedly be aided by 
training different from that of those who approach the modal 
condition, but as to what sort that training should be our concrete 
intuitions will be as good a guide as any theory psychology can 
now offer. In general superiority seems to show a comforting 
power to look after itself and get on with almost any training. 

Exceptional Defects. 

Existence and Amount. — The distribution of mental traits at 
the low end has not been determined, for the children accessible 
to the scientist in schools probably do not include all of the chil- 
dren defective in any important particular. Most of those who 
are very deficient in general intelligence are sure to be secluded 
at home or in institutions. Some of the mornl defectives will be 
in reform schools, or will be habitual truants or the companions 
of thieves and tramps, or will ho in tlio care of private schools 
or tutors. To a less extent those very deficient in momory or 




126 EDUCATIONAL PSYCHOLOGY 

abstract power or nervous control will tend to disappear for 
a longer or shorter time from the schools. It is probable that 
the distribution in many cases would deviate somewhat from 
the normal, taking a form like figure 47. The increase of 

defectives over the probable fre- 
quency would be due to the 
action of environmental forces 
which may lower a person from 
Fig. 47. almost any station but do not 

raise him far. For instance 
there seem to be many more people totally blind than just able to 
see, the passage from good eyesight to blindness being more fre- 
quent than the opposite. 

Exceptional inferiority characterizes some members of the 
human species in almost every mental trait or combination of 
traits. 

The list given on page 124 is appropriate here. Attention 
may also be called to defects of the senses ; defects of attention ; 
defects of nervous action, e. g., chorea; to the cases where a 
very great amount of a trait is a defect, e. g., cruelty or the instinct 
to possess oneself of what one desires ; the minor automatisms, 
such as biting the nails or counting groups of objects; morbid or 
useless impulses, such as touching every tree one passes ; and f eti- 
chisms, e. g., gi-eat affection for a red rag. 

Causation.— T\^Q causes of exceptional defects are the same as 
of exceptional superiority, but, as has just been said, environ- 
mental causes play here a more important role. Their action has 
been carefully studied only in the case of defects of sight, hear- 
ing, nervousness, choreic disturbance, general intelligence and the 
psychological defects with which medical practice deals. To the 
medical literature on these topics the reader is referred with the 
warning that precise quantitative statements will unfortunately 
rarely be given. 

i^ia^rnom.— What was said about symptoms in the case of ex- 
ceptional superiorities may be applied equally here. In the case 
of general lack of intelligence there will be some special facts to 
be noted. Such additional information is also at hand in the case 
of those other defects which have received the attention of medical 



EXCEPTIONAL CHILDREN 



I'JT 



science. The reader is referred to text-books on sense defects, on 
children's diseases and on idiocy and imbecility. 

Control— SVe know almost nothing about the remedial action 
of special forms of training upon those mental defects which 
medical practice has disregarded. Leaving one side such means 
as should be prescribed and administered by a physician, we may 
make the following recommendations : 

For nervousness: out-of-door life, much absolute rest, free- 
dom from competitive work and the exciting features of school 
and social life, but not from participation in both physical and 

mental work. 

For hysteria: out door life, removal from the home environ- 
ment, calm but insistent training in good habits, the example of a 
well-balanced, unemotional teacher, objective interests in nature, 
industry and human affairs, freedom from the exciting features of 

school and social life. 

For general intellectual weakness : removal to a special insti- 
tution, a stimulating physical and mental environment (though 
not for the few cases complicated with great nervous irritability), 
stirring physical play, out-of-door life, systematic stimulation of 
the senses and of curiosity, the arousal and direction of bodily 
movements, systematic physical training. 

The teacher or the consulting psychologist needs the coopera- 
tion of the physician in almost all cases of mental defect. Their 
causes, symptoms and relief are all connected with physical 
changes. These are sometimes apparent to the ordinary prac- 
titioner, as in defective school work due to indigestion or nasal or 
throat obstructions; sometimes apparent to the specialist, as m 
defective ability to read and spell due to retinal defect ; sometimes 
unrecognizable but yet doubtless existing, as in defective ability 
to form general and abstract notions. 

General Mental Defect. 
The psycholog}^ of those deficient in general intellect (idiots, 
imbeciles and the feeble-minded) has been >liscussed at some 
lenoih by many students. The chief questions concern classifa- 
catLn, causation, symptoms and treatment. The aim of this sec- 
tion will not be to review the facts and opinions WvM have been 



128 EDUCATIONAL PSYCHOLOGY 

stated, but simply to help the reader to study the literature of the 
subject intelligently. 

English writers agree in using the terms idiots, imbeciles and 
feeble-minded to refer in order to the three lowest conditions of 
intellect. This common use makes the terms very convenient, 
but it is certain from our knowledge of the distribution of mental 
traits that any effort to separate sharply idiocy from imbecility 
and the latter from feebleness of mind must fail. The words are 
but names used roughly for sections of a continuous surface of 
frequency. The obvious thing to do is to arrange a scale of in- 
tellect and describe that of each individual by his precise station 
on that scale, not by a vague name. 

iN^umerous more detailed classifications have been proposed, 
some on the basis of mental traits, e. g., the degree of capability 
in attention, the capacity for feeling relationships, the efficiency 
of the senses and motor apparatus ; some on the basis of the con- 
ditions accompanying them, e. g., a classification into paralytic 
idiocy, epileptic idiocy, syphilitic idiocy, etc. ; some on the basis 
of causation, e. g., a classification into congenital and acquired. 

The fact is that the varieties of human nature referred to by 
the words idiot, imbecile and feeble-minded, are numerous, that all 
sorts of combinations of mental qualities, accompanying diseases, 
causes and physical stigmata occur and that no simple classifica- 
tion can be adequate for all purposes. To grade idiots before 
courts of law or for asylum treatment a classification by mental 
ability as measured by attentiveness or some other mental traits 
may be best; to provide for medical treatment their separation 
into groups according to concomitant diseased conditions may be 
wise; for medical science the brain changes correlated with the 
mental conditions may be the key to the useful classification ; and 
so on through possible classifications for prophecy of ameliora- 
tion, for educational treatment, for psychological analysis, etc. 

I suggest as one of the most fundamental and useful classifi- 
cations a division into: (1) Those whose condition is due to 
original nature, who hold the position in the scale of intelligence 
which the make-up of their germs decreed, and (2) those who by 
accident or disease have been displaced downward from their orig- 
inal positions in the distribution scheme. The condition of 



EXCEPTIONAL CHILDREN 129 

members of the first class should as knowledge advances be capable 
of early diagnosis ; they should possess many characteristics in 
common and allow of further subclassification ; medical treatment 
would be relatively inefficient, but from wise educational and 
hygienic control we should expect much. The second class would 
present fewer characteristics in common ; strictly medical or sur- 
gical treatment would be of more importance than educational 
training; they should be studied in connection with mental dis- 
eases in general. Roughly it would be fair to say that for the 
first class we need psychologists and special schools, while for the 
second we need physicians and hospitals. 

It seems desirable further to separate children who are feeble- 
minded and are destined to remain so from those who are simply 
backward in mental growth and may eventually reach a fair sta- 
tion. We know that in physical growth some children who from 
six to twelve or thereabouts are far below average stature for their 
age, in later years make up part or all of the deficiency, and there 
are many reasons for believing the same to be the case with mental 
growth. The essentially dull should never be confused in theory 
or in actual treatment with those temporarily deficient. 

To the discussions of the causation of idiocy, imbecility and 
feebleness of mind in the standard texts I have nothing to add 
save that where so complex and so interrelated causes are studied, 
great help will come from more precise measurements of amount 
and from estimating the efficiency of partial causes by the coeffi- 
cients of correlation between them and their supposed effects, and 
between different ones amongst them. 

In the case of the symptoms of these conditions also, precise 
measurements with objective tests would permit an advance in 
knowledge which is impossible so long as cases are studied by an 
imdefined general examination and described by the loosest of 
adjectives. 

Amongst the recommendations for educational treatment those 
which are in accord with the following facts should be given 
especial weight: (1) Learning by the unconscious selection of 
reactions which produce pleasure and elimination of reactions 
which produce pain, is widespread throughout the animal kingdom 
and may be depended upon when learning from explanation, in- 



130 EDUCATIONAL PSYCHOLOGY 

sight and general principles is impossible. (2) The lower the 
mental capacity of an individual the closer in time must the pain 
or pleasure follow the reaction. (3) The connections between 
impressions and obvious movements of the body are more easily 
formed than between impressions and ideas or the more subtle 
movements of the muscles of the face, throat and trunk which 
perhaps always parallel ideas. The first type of connections may 
be formed in individuals incapable of the second. The so-called 
kindergarten and manual training methods are therefore particu- 
larly suited to defectives. (4) Mental defect often involves a 
sluggishness of action on the part of the nervous system which 
makes a rapid succession of stimuli interfere with each other and 
result in mental confusion, and necessitates the continuation of the 
same stimulus over a long interval or its repetition. (5) The 
extreme narrowness of the field of attention and the inabilitv to 
control sudden alternations of attention from one topic to another 
and back make it necessary for the teacher to take up but one small 
issue at a time, to progress along one single line. (6) Knowledge 
of relations, including appreciation of general and abstract no- 
tions and the symbols for them, is practically beyond the capacity 
of these inferior minds. It is therefore wisdom not to pretend 
to give it and economy not to try. They need sense training, 
object lessons and concrete work throughout. (7) Suggestion is 
potent here as elsewhere. By treating the feeble-minded like nor- 
mal children as far as is possible we help to make them more 
normal. They should have their school, church, entertainments, 
trades, excursions, etc. They should not be made to appear pecul- 
iar in dress or encouraged in eccentric habits. 

Exact Measurements of Exceptional Children. 

Johnson* made in the case of 72 feeble-minded and idiotic 
children measurements of the memory span for digits, of certain 
features of motor control and of the time of uncontrolled associa- 
tion of ideas. It is difficult to interpret his results because he 
does not give the total distributions nor provide the most desira- 
ble data for comparison with ordinary children. His most elab- 
orate study is of the memory span for numbers, where he dupli- 

* Ped. Sent., Vol. III., pp. 246-301. 



EXCEPTIONAL CHILDREN 131 

cates certain tests made by Galton witli 44 feeble-minded girls. 
Comparison with normals is only roughly possible, owing to dif- 
ferences in the selection of groups by Jacobs, Bourdon and Bolton. 
But approximately 25 per cent, of idiots do reach or exceed the 
ability reached or exceeded by 50 per cent, of ordinary children. 
This difference is not much greater than that between boys and girls 
in spelling ability. As Johnson points out, it is more likely to be 
due to differences in habits of attention than to a difference in mere 
retentiveness. 

In the tests of motor control the feeble-minded were inferior 
to ordinary children, but so far as I can estimate from the incom- 
plete figures given, not more so than in memory span. I quote 
the facts given. In the swaying tests, larger figures mean less con- 
trol over movement. 

''Swaying tests were made on seven boys and five girls with 
the ataxiagraph. I^ine of these children were school cases. The 
averages were as follows : 

7 boys [feeble-minded], average age 13 years, 6.52 cm. by 4.44 cm., 
eyes open. 

5 girls [feeble-minded], average age 13.4 years, 5.76 cm. by 4.7 cm., eyes 
open. 

"Hancock's tables show the following results {Fed. 8em., Vol. 

III., No. 1): 

35 boys, 5 years old, 5.8000 cm. by 5.2228 cm., eyes open. 
22 girls, 5 years old, 5.7773 cm. by 4.9500 cm., eyes open. 

"Tests were made in order to find the ratio of the rapidity of 
shoulder to finger movements. The number of revolutions that 
the arm could make in ten seconds was recorded, and also the 
number of times that the hand could be opened and shut in the 
same number of seconds. The averages were as follows ' ' : 

Shoulder. Finger. RiUio. 

8 feeble-minded boys, average age 13.6 21.00 17.62 100: 81. 

8 feeble-minded girls, average age 16.1 21.25 20.25 100: 93.2 

13 boys, normal, average age 13.6 26.85 25.15 100: 03.6 

12 men, normal 25.4 32.7 100 : 128. 

5 women, normal 22.0 32. 100 : 141. 

In the time of association (of word witli word) the greatest 
difference was found. Not one of 30 feeble-minded tested h{id 
as quick a rate as the average of ordinary cliildren, the figures 
being : 



J32 EDUCATIONAL PSYCHOLOGY 

Average. Slowest. Quickest 

30 feeble-minded boys averaging 13.3 years 5.35 see. 10.70 2.70 

10 ordinary boys 2.61 3.47 2.06 

As to the nature of the ideas associated with the words given, 
" a comparison of the tables shows a much greater tendency upon 
the part of the feeble-minded to make simple objective (rather 
than logical) associations." 

There is an ill-defined group of children separated roughly 
from others of their age by the fact that they do not get on in 
school work and still are capable enough in many matters to make 
unjustifiable the titles idiot, imbecile or feeble-minded as com- 
monly used. Theoretically this group is composed of a number 
of different species of individuals. Some fail in school work 
because of defects of vision or hearing which their teachers fail 
to allow for. Some are nervous, fretful and easily distracted. 
Some are extremely unimpressionable and slow. Some lack only 
the capacity to deal with abstract ideas and symbols and succeed 
well enough in concrete acquisition. Some may even possess full 
capacity and lack only interest. Some are weak in intellect 
throughout, belonging on the border line between the brighter of the 
feeble-minded and the duller of the so-called normal children. 
Some are simply too immature for the work. Practically the 
group possesses the unity of a negative characteristic, inability to 
profit by the methods of teaching the usual subjects, reading, 
writing and arithmetic. In any school of a thousand pupils the 
principal can pick out from twenty to forty such children who 
are the despair of their teachers, a hindrance to their classmates 
and a source of worry to their parents. Even after sense defects 
are corrected or allowed for, after adenoids have been removed, 
even when wise teaching prevents excitement and nervous worry 
and arouses interest, a majority of these will be just as they were 
before. The group thus left has never attracted the attention 
of medical science or of educational psychology to the extent that 
its practical importance deserves. 

Miss ISTorsworthy* has compared such a group of 30 girls, 
8-13 years old, picked out from about a thousand in a city 
school on the ground of inability to profit by the regular school 
* In a study as yet unpublished. 



EXCEPTIONAL CHILDREN 133 

work, witli ordinary children of the same age who lived in 
the same environment, attended the same school and were meas- 
ured by identical tests given by the same individual. In giving 
instructions explanations were made very clearly and the process 
required was also shown by samples put upon the board. The 
measurements taken were as follows : 

1. Height. 

2. Weight. 

3. Body temperature (taken at the mouth). 

4. Pulse. 

5. Rate of movement; tested, (a) by the number of crosses made in ten 
seconds (two trials) ; (b) by the number of up-and-down movements made 
in ten seconds (two trials). 

6. Accuracy of movement; tested, (a) by the number of touches made 
in drawing a line between the lines of figure 48; (b) by the regularity and 
evenness of the figures made in the tests for the rate of movement. 




Fig. 48. 

7. Efficiency of perception (rate and accuracy combined). Tested by 
the A test. 

8. Efficiency of perception (rate and accuracy conihiiicd) ; tested by the 
a-t test. 

9. Delicacy of discrimination of length; tested by tlie variable ermr in 
drawing a line equal to a 10-cm. line (ten trials). 

10. Efficiency in a test of perception and movcnient combined, viz., the 
time taken to insert dilTerent shaped blocks into a board made with depres- 
sions to fit them. 

11. Memory of unrelated words; number remembered mil o\ ini aUcv 
a single hearing (two trials) — red, dog, day, tree, buy. never, sick, song, 
boy, box, long, green, arm, incli, tnio, run, dress, break, friend. 



134 EDUCATIONAL PSYCHOLOGY 

12. Memory of related words; number remembered out of ten after a 
single hearing (two trials) — school, teacher, book, desk, pen, read, write, add, 
spell, word, river, water, brook, flow, ice, cold, winter, snow, sled, skate. 

13. tJemi-logical memoiy; memory of four simple dictations, viz., (1) I 
have one head, two eyes, two hands and ten fingers. (2) I sit in my seat. I 
read from a book. I write with a pencil. (3) One and two are three. Three 
and four are seven. Five and six are more than ten. (4) In the morning I 
go to school. After school I play. At night I go to bed. 

14. Ability in the formation of abstract notions, the appreciation of 
relationships and the control of associations; measured by the following 
tests: (A) to write the opposites of a given list of words; (B) to mark 
those words in a list which are names of things; (C) to write a word repre- 
senting some kind of the thing named by a given word; (D) to write a word 
representing some thing of which the thing named by the given word is a 
part; (E) to write the opposites of a list of words, the converse of the list 
used in A, after the correct responses for A have been read to the class. 

The detailed results of tlie comparison can not be given here. 
Their general outcome is perfectly clear. In the physical traits 
there is very little difference except in the rise of temperature at 
the mouth in the course of twenty minutes of work at the tests. 
This invariably occurred with ordinary children, but in only 60 
per cent, of the special cases. The pulse rate of the special 
cases is a trifle lower. The difference increases as we pass from 

physical traits to tests of move- 

ment, then to tests of verbal 

-y^-* .3 -i -I a *i ti ti ,t r, memory and then to tests of per- 

ception, but even in the last case 




Fig. 49. The abilities in tests of controlled the Special CaSCS rank about 

associations and conceptual thinking of 73 . i i i 

mediocre 9-year-old children and 19 very dull with the loWCr half of ordinary 

children 8.5-13 years old. The upper figure is "^ 

for the mediocre 9-year-olds. children. But with tCStS 12, 

13 and 14 the difference becomes increasingly greater, until in 
the last the special cases come to rank as the extreme end of the 
school population of their age (Fig. 49). 

The one chief and essential characteristic of these children 
is thus their inability to think in symbols or with relationships 
or in such a way as to let a number of processes combine to 
decide what a given thought or reaction shall be. Concrete facts 
they can think and respond to one by one, but they can not think 
in symbols that stand for groups of facts or elements in facts, nor 
can they think facts together in causal or other series or respond 
correctly to related groups. In short they are the weakest members 



EXCEPTIONAL CHILDREN 135 

of a school population in thinking of the pure human type. Besides 
this main defect there is a slight diminution of mental vigor, 
quickness and tenacity along all lines. In no mental tests do 
they do quite as well, and they give us some reason to believe 
that as they grow older they will develop continually less and less 
rapidly than ordinary children and so fall farther and farther 
behind in the mechanical as well as rational capacities. 

Moral Defectives. 

There are no general conclusions based upon exact measure- 
ments of moral deficiency and its causes and accompaniments. 
There is an abundance of ineffective detail stored up in medical 
comments upon so-called moral insanity and morbid impulses, in 
prison reports and in the minds of experienced schoolmasters. 
The greater complexity of the phenomena will always make the 
psychology of moral defectives more intricate than that of the 
feeble-minded. 

The one general truth which can be asserted is that all sorts 
of moral defects exist, are far from perfectly correlated and are 
due to a multiplicity of causes. There are extremes of cruelty, 
deceit, egotism, passion, knavery, destructiveness and of all moral 
traits conceivable. There are boys and girls notably defective 
in only a single respect and others in whom every meanness and 
vice seems to thrive. We imagine, however, and probably with 
justice, that the correlations between certain defects are particu- 
larly high, so that certain common types or more correctly features 
emerge. 

Such are perhaps types of moral defectives or features of 
moral defect characterized by: (1) Extreme predominance of the 
animal instincts, shown, for instance, by brutality and teasing, ex- 
cessive sexual appetites, fits of rage and sulking, unreasoning greed 
and malice; (2) extreme egotism and lack of appreciation of the 
feelings and rights of others; (3) extreme weakness of control nnd 
moral instability, sho^^'ll by susceptibility to all temptations and 
petty vices, alternations of affection with cruelty, anger with tears, 
peevishness, untrustworthiness, — an hysterical and irros]xinsible 
mental type, bad more because of the weakness of good habits than 
because of the strerigth of evil iin pulses ; (4) tlio existonoo of one or 



136 EDUCATIONAL PSYCHOLOGY 

more morbid impulses of an immoral sort. Children may have in- 
tense desires to cut or tear without being generally extremely cruel, 
to run away from home and live tramp life without being generally 
extremely disobedient, to be kleptomaniacs but generally fairly 
honest, incendiaries without general destructiveness or to be sex- 
ually disordered without being of excessive passions. 

Of course there is no rigid adherence to these types. Com- 
binations, intermediate conditions and children falling outside 
these groups all exist. The extent to which such a grouping of 
cases is allowable or useful can be told only after measurements 
of the correlations between special immoral traits have been made. 

Our feature 1 would seem likely to be due to original nature 
accentuated or relieved by training; feature 2 to be also an orig- 
inal defect in sympathy coupled with lack of abstract intellectual 
power and commonly made worse by the spoiling and selfishness 
of parents; feature 3 to be due to original nervous instability 
displayed in moral more than intellectual matters as a conse- 
quence of feeble and vacillating parental interference. The mor- 
bid impulses of 4 are probably more ingrained in original nature 
and less influenced by environmental conditions. 

General moral defect commonly involves intellectual inferior- 
ity. The brightness and precocity that seem to characterize many 
cases of types 2 and 3 are really glibness, pertness and lack 
of restraint. It is therefore likely that general moral defect is 
due in part to generally inferior nervous organization. 

Exceptional Rates of Growth. 

Precocity, retarded development* and arrested development 
are terms loosely used to refer to children who are exceptional in 
the rate of mental growth. As we find them in books they hardly 
mean anything more definite than very rapid growth^ very slow 
growth and absence of growth. But they may be made exact 
descriptive terms if we establish standards of change with age 
from which exceptional rates may be measured. 

* The term retarded development is at times used not for an undefined 
slowness of growth, but for a slowness in growth which will later be made 
up. I shall therefore replace the two uses of the single term by the two 
terms slow growth and delayed growth. 



EXCEPTIONAL CHILDREN 137 

By far the best arrangement would be to give stations above 
or below the average in rate of gTowth in just the same way that 
we do in the case of static conditions of a trait, and to speak in 
terms of these numerical stations rather than in the vague terms 
supernormal, normal, subnormal, etc. When any individual's 
rate belongs to a distinct species of mental growth the fact can 
easily be made clear by giving the total distribution scheme as well 
as his station therein. 

As a matter of fact precocity, retarded development, etc., are 
rarely measured thus directly from the rate of change. Instead 
they are inferred from the fact that an individual is above or 
below the condition usual at his age. The term retarded develop- 
ment, for instance, is thus applied to a case which may be one 
of slow rate of growth at the time of observation, or of a slow 
rate in years long past, or of low initial station. This is unjusti- 
fiable. Exceptional degrees of ability should be dealt with apart 
from exceptional rates of change in ability. 

Precocity. 

There is a popular opinion much encouraged by physicians 
that children who in early life gi'ow mentally very rapidly and 
so attain high stations are likely to come to grief, and be soon 
surpassed in health and mental ability by their less precocious 
fellows. It is an illustration of the suj)erficiality of human 
thinking that so unhesitating an acceptance should be given to the 
paradox that rapid mental improvement from to 10 should be 
an evil, but from 20 to 35 the greatest of blessings. For if we 
pass beyond a few striking examples which prove nothing it is 
hard to see any evidence for the first statement of the paradox. 
On the contrary bad physique and nervousness accompany dull- 
ness oftener than brightness; and early mental superiority is 
prophetic of later. 

Thus Warner found abnormal nerve signs in the dullest T^/^ 
per cent, of children over nine times as frequently as in the other 
921/2 per cent. (55.39 per cent, and 6.08 per cent.) and low 
nutrition over eight times as frequently (10.12 per cent, and 1.91 
per cent.).* 

* Calculated from the tabic on page 24t) of tlie ' Study of CliiMroii.' 



138 EDUCATIONAL PSYCHOLOGY 

These correlations are in the writer's opinion much too high, 
owing to the fact that dullness was not estimated objectively. But 
even if we cut them down one half they still show a marked an- 
tagonism between brightness and bodily or nervous disorder. 

In the case of 10 children chosen at random, for each of whom 
I had records of ability in the school work of grade 4 and of 
grade 7 or 8, that is at about the tenth and about the fourteenth 
and fifteenth years, I find the relationship between the ability 
shown in the early and that shown in the later period to be not 
at all one of antagonism but of resemblance. The Pearson co- 
efficients are: 

r for 4-7 grade (40 cases) =:-|-. 18 

r for 4-8 grade (30 cases) =+.31 

The mistake seems to have arisen from a number of fallacies. 
First, physicians meet with cases of physical or mental break- 
down in mentally superior children. They still oftener meet 
similar cases in mentally inferior children, but the former cases 
excite more pity and are more interesting and dramatic. They 
tend therefore to remain in the physician's mind while the others 
fade. Second, an interest in and acquaintance with topics suit- 
able for older people, such as sex, theology or adult human social 
relations, is often taken to be the sign of a precocious mind. !Now 
these phenomena are often morbid and may therefore well go with 
an unstable mental organization and so be somewhat prophetic of 
disaster. But they are not per se indicative of superior mental 
growth. !For the few supernormal children who exercise their 
gifts on such questions there are many who are ahead in school, 
play, leadership and accomplishments. We can not take the word 
precocious in the bad sense of unbalanced superior gifts and 
argue from premises thus obtained to conclusions about precocity 
in the sense of generally supernormal mental growth. In the 
third place, physicians often take the word of the parents for the 
children's precocity. It then means probably mere forwardness, 
ready talk, so-called ' bright ' sayings and doings and even im- 
pertinence. These all witness to subnormal mental ability dis- 
guised by lack of inhibition. The quiet child thinks of many 
much brighter things to say but also has the strength of mind 
not to say them. Lack of inhibition and impertinence are pro- 



EXCEPTIONAL CHILDREN 139 

phetic of poor mental growth in the future because they are in- 
dicative of it in the past and present as well. Finally it must 
be said that the average medical man in his ignorance of the 
subtle hereditary and environmental causes of mental breakdown 
grasps at any cause he can. If the child is dull, mental weak- 
ness is to blame; if he is bright, precocity! 

Slow Growth. 

In the absence of any quantitative studies of slowness of 
growth, this section will be limited to brief comments upon the 
question as to whether slowness of growth in one mental trait 
implies equal slowness in the growth of others, and the question 
of the desirability of a slow mental growth. 

Slowness of mental growth is undoubtedly specialized, though 
to just what extent is not known. An obvious illustration is 
given by the sex instincts, which may mature far in advance of 
or far behind the intellectual powers. So also with social facility 
or musical talents. The resemblances between traits in an indi- 
vidual in their rate of maturing are, however, probably much 
greater than in their final condition. 

Slowness of mental growth is in general an unfavorable sign. 
It is correlated slightly with low original capacity and low ulti- 
mate attainment. In some cases, of course, the growth is only 
delayed and the individual who seems to be far behind may come 
out well ahead. Moreover, as in height the boys who grow less 
than the average before thirteen grow more than the average after- 
ward,* so in mental traits retardation before puberty may mean 
acceleration after it. Still by and large slowness is related to 
unfavorable conditions. 

The opposite view, a corollary to the superstition about pre- 
cocity, has gained credence, I fancy, first because of the supposed 
slowness in maturing of superior races, and secondly because of 
the supposed ill success at school of gifted men. But the ap- 
parent mental attainments of children of inferior races may be 
due to lack of inhibition and so witness precisely to a deficiency 
in mental growth. Moreover we can not argue from inferior races 
to inferior members of one race. The failure at school work of 

* For this fact I am indebted to Professor Franz Boas. 



140 EDUCATIONAL PSYCHOLOGY 

children destined to become eminent men is a myth. The per- 
centage is far higher for thieves and paupers and lack-wits. 

Inefficiency due to slow mental growth, especially in those 
cases where the future will prove it to have been only delayed 
mental growth, must not, however, be confused with inefficiency 
due to inevitable incapacity. The correlation would have to be 
1.00 to permit the interchange of these terms as synonyms. 

Accurate tests to differentiate inherent incapacity from im- 
maturity would seem to be of great practical value. They would 
prevent the injustice and discouragement due to mistaking the 
second for the first and the false hopes inspired by mistaking the 
first for the second. An approximation to such a differential 
diagnosis can be made by using the following tests. 

A. Tests of Maturity Chiefly. 

Motor control ( rate of tapping, rate of making crosses, maze tests ) . 
Memory of unrelated words, pictorial forms, etc. 
Perception (A test, a-t test, geometrical forms test). 
Delicacy of sense discrimination (of length and of weight). 

B. Tests of Intelligence Chiefly. 

Logical memory (memory of passages that involve connected and sys- 
tematic exposition or argument). 

Controlled association ( alphabet and easy opposite tests or the like ) . 

Perception of relations (filling up the blanks in passages like the fol- 
lowing) : 

In everything that we do . . . need ... be both quick . . . careful . . . 
we are . . . quick we do not get much done we care- 
ful we do not do our work . . . well . . . others. It is better to be careful 
. . . than to be quick . . . the best worker . . . the one . . . can do . . . 

things . . . do . . . well we can not all be the best, we can . . . 

improve. 

Let us suppose a boy who does not get on well in school to be 
tested and given stations in A and B with reference to the median 
for his age and sex. The lower his station is in A and the higher 
it is in B the more chance there is that he will grow out of his 
difficulty. Conversely the higher his station is in A and the 
lower it is in B the greater is the probability that he is essentially 
dull. 

Arrested Development. 

The phrase ' arrested development ' is used in medicine to 
mean just what it says. Bodily organs including the brain may 
remain stationary or nearly so in one individual at a period when 



EXCEPTIONAL CHILDREN 141 

in the great majority they are growing. In the case of the brain 
there may be no arrest apparent in gross structure, and yet the 
neurons themselves may not have attained their full development 
in complexity and delicacy. If we knew fully the history of the 
growth (normal or pathological) of the neurons themselves, we 
could probably extend the conception of arrested development to 
the entire field of mental life and distinguish in post-mortem ex- 
aminations between the clodhopper who stagnates mentally after 
a score of years, and the Gladstone or Virchow whom the allotted 
span of life leaves still progressing, as we now distinguish be- 
tween the brain of an amaurotic idiot and an average boy. It 
seems therefore justifiable to use the phrase arrested development 
from the psychological point of view in the case of any mental 
trait in any individual which remains stationary or nearly so at 
a period when it ordinarily is advancing. Medical men com- 
monly apply the phrase to only those well-marked cases of general 
mental weakness which are correlated with gross developmental 
defects of the body or brain. 

Arrest may be temporary or permanent. In the former case 
sickness, low nutrition and disuse are the probable causes ; in the 
latter definite brain lesions or original lack of developmental 
force. It may be general or specialized. In every trait perma- 
nent arrest comes sooner or later to almost all of us. The dif- 
ferences amongst men are not in its presence or absence but in 
its date. There is, of course, no absolute date for any trait 
which is ' normal ' for it. The date is variable, and abnor- 
mality here as elsewhere can mean only some arbitrarily chosen 
difference from the average. 

It is a common habit of pseudo-scientific writers about educa- 
tion to decry one thing or another in school practice on tlic ground 
that it causes arrested development. Such speculations lack any 
adequate basis of fact. We do not know whether any school 
methods can, much less whether they do, cause sj)ecial or general 
arrest of mental growth. 



CHAPTER XIII. 

THE RELATIONSHIPS OF MENTAL AND PHYSICAL TRAITS. 

It has been fashionable to proclaim a close relationship be- 
tween mental and bodily efficiency, to suppose that desirable 
mental conditions go hand in hand with desirable physiques. 
These statements in spite of their plausibility are so vague and 
undiscriminating that any one of scientific training would expect 
them to need much modification, and the argTiments adduced 
hardly bear the scrutiny of any one who is aware of the real 
complexity of the facts. Moreover what we mean by asserting 
a connection between bodily well-being and mental superiority 
varies according to our use of the terms. The former may mean 
for us, (1) stature and weight, (2) strength, (3) freedom from 
recognized anatomical deformities or bodily diseases, (4) motor 
control (the opposite of nervousness) or (5) motor skill (dex- 
terity, adroitness in executing movements). The latter may 
mean (1) mental health or balance (relative freedom from in- 
sanities, eccentricities, morbid impulses and habits, etc.) or (2) 
mental ability (defined as the ability to do those mental tasks 
which men in general try to do). There is not then one single 
problem, but a group of ten separate problems. All might con- 
ceivably have identical answers, but the chances would be great 
that the relationships in the ten cases would differ in important 
respects and to a notable degree. 

Indeed we may properly claim that the analysis should be 
carried much farther and that the really fruitful studies will be 
of the relationships between each particular species of bodily con- 
dition and each particular species of mental ability or of mental 
health; that the specialization of relationships is so extreme that 
within any one of the ten cases just mentioned there will be dif- 
ferent degrees of relationship. Thus deformities of the palate 
may have a significance which deformities of the joints do not; 

142 



RELATIONSHIPS OF MENTAL AND PHYSICAL TRAITS 



143 



epilepsy and paralysis obviously have a significance that dia- 
betes, small-pox and typhoid fever do not.* 

* An instructive instance of such specialized relationship is the case of 
the body temperature measured in the mouth and general intelligence as 
manifested in school work. Ireland (' Mental Affections of Children,' p. 45) 
and others have noted that the temperature of idiots is frequently very low. 
Prescott {Pedagogical Seminary, Vol. IX., pp. 437 and 438) found that of 
10 children whose temperatures were the highest out of 71, 80 per cent, 
ranked excellent or good in studies, while of 7 children whose temperatures 
were the lowest only 43 per cent, ranked good (none ranking excellent). 

Miss Norsworthy (in an unpublished study) found the temperature at 
the mouth in the case of 20 very bright girls, 31 nine-year-old girls picked 
at random from the third-year classes of a public school and 38 very dull 
children ranging from 8 years months to 13 years 6 months. The results 
are given in Table XIII. 

TABLE XIII. 
Temperatxjbe at the Mouth of School Children. 





Bright. 


Ordinary. 


Very Dull. 


95.4 up to 






1 


.6 









.8 









96.0 









.2 






1 


.4 




2 


2 


.6 







1 


.8 










97.0 




1 





.2 







3 


.4 







1 


.6 


1 


3 


1 


.8 





2 





98.0 


1 


2 


4 


.2 


1 


2 


3 


.4 


1 


7 


4 


.6 


2 


3 


4 


.8 





3 


3 


99.0 


2 





6 


.2 


3 


1 


2 


.4 


2 


3 


1 


.6 


2 


2 





.8 


3 







100.0 


1 




1 


.2 


1 






Median, 


99.3-1- 


98.5 


98.5 


Average, 


99.2-f 


98.4-f 


98.3— 



The last two series were tested before and afliT simple tests of mental 
abilities. Miss Norsworthy noted that no (iiir nf llic ordinary childn-n 
showed a fall of temperature, while a third of the dull ones did. The 
medians for the temperatures after the tests were: Ordinary nine-year-olds, 
99.1; very dull oliildren, 98.8. 



144 EDUCATIONAL PSYCHOLOGY 

After the discovery of a relationship there is the equally im- 
portant task of interpreting it. The common inference, for ex- 
ample, that if freedom from recognized anatomical deformities 
and bodily diseases goes with superior mental ability, we may 
improve the latter by securing the former, is by no means neces- 
sary. In original nature there might be a correlation between 
the two traits, yet alteration of the one by hygiene or medicine 
or surgery might leave the other uninfluenced. 

It is always a special problem to determine how far improve- 
ment in one trait, physical or mental, alters any other. In gen- 
eral, as we have already noted in previous chapters, a relationship 
found may mean not that there is an essential connection in 
human organization between the two, but only (A) that we have 
been misled by the fallacy of selection, or (B) that growth influ- 
ences both traits alike, or (C) that one trait causes the other in- 
directly through its influence upon the conduct of life, or (D) 
that both are brought about by some artificial outside cause which 
need not exist or so act, but happens to in the present organiza- 
tion of society. It may mean something still different. 

Illustrations of these different cases are the following: 

(A) Physicians are more likely to notice defects in mental 
health in cases presenting also physical deformity and disease, 
for they are more frequently consulted when the latter are also 
present. Their estimates of the relationship will therefore be on 
the basis of an unfair selection of cases and will be too high. 

(B) As boys and girls grow with age they gain in mental 
capacity. We find therefore a relationship between stature and 
mental ability, but if we could get a group of identical maturity 
this relationship might not appear. Thus there is no correlation 
between the ratio of height sitting to total height and mental 
ability, but if we took children of all ages we would apparently 
find such, for with age the ratio of the length of the trunk to total 
length decreases. 

(C) Diseases of one sort or another might debar individuals 
who were by organization of average mental ability from the use 
of books, laboratories, etc., or drive them to farming or manual 
labor and so eventually reduce their intellectual stations below 
the average. 



RELATIONSHIPS OF MENTAL AND PHYSICAL TRAITS 145 

(D) Ignorance and carelessness in parents would favor the 
development of diseases and deformities in children and also the 
development of stupidity, mental laziness and bad methods of 
mental work, thus producing a positive correlation. 

To study adequately relationships between physical condi- 
tions and mental health requires a knowledge of medical science 
beyond the reach of the writer and presumably of the readers of 
this book. Suffice it to say, therefore, that the precise relation- 
ships have not been determined; that 3 and 4 surely have some 
essential relationship with mental health and that 1, 2 and 5 
have much less, if any, and that there is a clear specialization 
of relationships within 3 and 4. 

The relationships between physical conditions and mental 
ability I shall now deal with seriatim. 

Stature, Weight and Intellect. 

This problem apparently so simple is really very intricate. 
I shall dispense with a critical resume of the evidence and deal 
summarily with the main conclusions. 

The correlations between stature and mental ability in adults 
have not been computed. There are some indications of a slight 
direct correlation. College students are taller than the average 
population. Galton found eminent English men of science to 
be half an inch taller than their fathers. But the interpretation 
of such facts is complicated, and the amount of the correlation 
is unknown. It is surely very small and its causation is probably 
complex. We may however be rather glad tlian otherwise to 
find the stature of the race increasing. 

Porter^ found the ten-year-old children in liighcr grades 1o 
be heavier and taller than the ten-year-old children in lower 
grades, and similarly for all ages. He argues that there is a 
direct relation between brightness and superiority in weight and 
stature. The argument is: Children in high grades are larger 
than those of the same age in lower grades. Among children of 
the same age those who have gotten on farthest in soliool are the 
most intelligent. Therefore size goes with intellect. The argii- 

* Transactions of the St. Louis Acadcmxj of Science, Vol. VI., pp. Uil 
and ff. 



146 EDUCATIONAL PSYCHOLOGY 

ment is doubly fallacious. First his facts do not prove that 
children in high grades are larger than those of the same age in 
lower grades, but only than those of the same year age. It might 
be, for all that he says, that all the 13-year boys in the eighth 
grade were 13 years and 182 days and all those in the third 
grade 12 years and 184 days old (he measured age to the nearest 
birthday). There might be almost a year's difference in their 
ages and the difference he found in size might be due to it. Some 
progressive difference in age between children in the same year 
of life who are in different grades there will surely be, those near 
the end of the year of age being more frequently in the high 
grades and vice versa. 

In the second place, as Boas* has noted in a criticism of 
Porter's results, children do not reach a given school grade early 
merely because of intelligence. Mental maturity decides in part 
the age at which they shall be sent from home, their ability to 
do school tasks and their promotion or retention iri a grade. 

This second criticism applies also to the reports of a similar 
though less extensive study by the Department of Child Study 
of the Chicago school system, f 

Gilbert,:}: Boas§ and West|| have compared the ranks of chil- 
dren in intelligence as estimated by their teachers with their 
physical standing with reference to their age and find a slight 
inverse relationship. I suspect that this method is not entirely 
free from objection. Some big twelve-year-olds who have been 
pushed ahead of others of this age because of physical and mental 
maturity will, we know from the Chicago report and from a prop- 
erly modified statement of Porter's results, be in a grade with 
children older on the average than they. The teacher, who makes 
all estimates by comparison within the class, may call such boys 
dull, though if they were with their own age she might judge 
them to be of average ability. Moreover in Gilbert's studies the 
sexes are not kept separate. Sex differences may distort the facts, 

* Science, New Series, Vol. I., 225-230. 

t Dated July, 1899, to July, 1900; reprinted from the 46tli Annual Re- 
port of the Board of Education of Chicago. 

t Yale Studies, Vol. II., and Univ. of Iowa Studies, Vol. I. 
§ Science, New Series, Vol. I., pp. 225-230. 
II Science, New Series, Vol. IV., pp. 156-159. 



RELATIONSHIPS OF MENTAL AND PHYSICAL TRAITS 147 

On the whole it seems wisest to expect both a correlation of 
rapidity in physical with rapidity in mental growth and a very 
slight correlation of rapidity in physical growth with intellectnal 
gifts. 

The relationship between bodily strength and intellect in 
adults is not known, but there is certainly no marked connection. 
In children rough attempts to measure the relationship have been 
made by the Department of Child Study of the Chicago School 
System and by Dr. J. A. Gilbert. As with stature, in neither 
case was age determined closer than to a year. And the same im- 
perfect measures for intellect were used — school grade readied 
and relative position to the rest of the class in the teacher's opinion. 
As with stature, the first method showed a decided direct correla- 
tion and the second showed a zero or slightly negative correlation. 
Our previous criticisms hold here in the same way and for the 
same reason, the most likely conclusion being that there is a very 
slight direct correlation between intellect and rapidity of growth 
in strength. 

Deformities and Sickliness and Intellect. 
Warner* found a rather close relationship between what he 
calls 'developmental defects' and dullness; viz., that a child 
possessing the former was seven times as likely to be dull as one 
not possessing them. But his criteria for distinguishing children 
with developmental defects from children without them are cer- 
tainly arbitrary and inexact and likely to bend one way for stupid- 
looking children and the other for bright-looking children. Worse 
still, his criteria for dullness are not even stated. "SMio picked out 
the dull children and how he did it are unanswered questions. 
So until his results are made more precise and corroborated by 
other observers they should be judged cautiously in llir liglit of 
general knowledge. Tlio same holds good of the (■(UTolntion 
which he finds Ix'twoen sickliness or a poorly nourished condition 
and dullness (that the latter r-ondition goes witli the former nearly 
^even times as often as with its opposite). In both cases the 
habits of a physician would be such as to make the correlation too 



high. 



* ' study (if Cliilflron,' p. 24!). 



148 EDUCATIONAL PSYCHOLOGY 

Bad Nervous Action and Intellect. 
Warner's statistics are again tlie chief source of information. 
He finds that children who manifest marked signs of nervous dis- 
order such as involuntary twitching, asymmetrical posture, etc., 
are about 11^ times as likely to be dull as are those who do not. 
The same judgment as before must be made concerning the relia- 
bility of his estimate, especially since another investigator* finds 
that " The feeble-minded were remarkably free from the nervous 
twitchings and the bad hand postures mentioned by Dr. Warner. 
[Out of 72 cases] I found one case of convulsive hand and two 
of twitching fingers. In two cases the arms twitched but not the 
fingers. Occasionally the thumbs drooped." 

Motor SJcill and Intellect. 

Dr. W. C. Bagley t has reported a study of this problem. 
Unfortunately he used reaction time as a partial measure of men- 
tal ability, calculated the correlation by a very inaccurate method, 
did not compare children of precisely the same age and made two 
gross errors in his figures. Reaction time we have seen (page 
32) to be very little symptomatic of mental ability. Within any 
grade the teacher's marks for mental ability (Dr. Bagley's other 
measure of mental ability) will probably be due to the comparison 
of brighter young pupils with older dull pupils, while motor abil- 
ity, which we know to improve steadily with age, will be low for 
the young and high for the older. To get the real relation be- 
tween the two we must work out the correlations for groups of 
children of the same age, all the individuals of each group being 
measured by the same standards for the two traits. Dr. Bagley 
used only a very coarse subdivision into groups 14-17 yrs,, 13-14, 
12-13, 8-11. 

With this too coarse grouping he gets the following results : 

Ages 14-17,those ranking in motor ability 962.1 ranked in mental ability 894.6 

" " " " 941.2 " " " 894.7 

" " " 930.5 " " " 927.3 

« " 908.0 " " " 929.3 

* G. E. Johnson, Pedagogical Semina/ry, Vol. III., p. 276. 
t * On the Correlation of Mental and Motor Ability in School Children,' 
Am. J. of Psy., Vol. XII., pp. 193-205. 



RELATIONSHIPS OF MENTAL AND PHYSICAL TRAIT,-; 149 



Ages ia-l4,t 


hos 


B ranking in 


motoi 


■ abilit 


y 967.9 rai 


nice 


1 in mental 


abili 


tyfiO.J.O 




« 




(( 




947.9 


t( 




K 


02 5. S 




t( 




(( 




935.2 


Si 




(( 


919.3 




(C 




« 




899.G 


l( 




(( 


930.7 


Ages 12-13, 


t< 




« 




943.3 


(< 




l( 


939.5 




it 




n 




921.0 


« 




«( 


927.0 




ti 




tt 




912.4 


« 




(( 


021.2 




« 




« 




887.6 


(( 




4» 


001.0 


Ages 12-12, 


(( 




« 




944.8 


(( 




<( 


952.2 




« 




« 




931.1 


(( 




<< 


950.1 




(( 




« 




912.8 


<( 




(( 


942.5 




li 




« 




881.4 


<( 




<( 


938.5 


Ages 8-11, 


l( 




« 




920.5 


a 




l( 


944.5 




a 




« 




902.2 


« 




(( 


948.3 




(t 




(( 




889.9 


(< 




tt 


958.0 




(( 




<( 




874.5 


cc 




tt 


934.2 


Average of 


all 


age groups 






.948.9 








920.0(8) 
929.3 









928.7(6) 


















916.2(0) 








033.8(7) 












890.2 








020.0(8) 



There is evidentlj no antagonism between motor and mental 
ability. By an error of some sort Mr. Bagley makes the first 
two averages of all age groups in mental ability 906. 8 and 009.3 
giving the appearance of antagonism, and so concludes that ' there 
is a general inverse relation between motor and mental ability.' 

If we take the 12-12" and 12-13 groups where the age <lif- 
ferences within the group are not so great, we fii;d a direct corre- 
lation. So far then as so inaccurate measurements as these can 
be taken to prove anything they prove that if we should compare 
children of the same age we should find a slight direct relation- 
ship between mental ability and motor ability. 

Gilbert in the two studies already so often quoted compared 
the rates of movement, for chihlren of the same year-ages who 
were rated bright by their teachers with ilio rates of those sim- 
ilarly rated average aiitl dull. in general those rated bright did 
better. The differences of the average and dull froin the briglit 
are given in the following table ('Xl\') first in absolute amounts 
and then in terms of tbc mean variations for boys and girls of 

•It must, include some 11 year.n old aii<l really he 11 12, for Dr. Bagloy 
states that the average age was 12.0. 



•150 EDUCATIONAL PSYCHOLOGY 

the age in question. For the reasons referred to on page 146 
we can not be sure just what these differences mean. It should 
be noted that the differences between bright and average are very 
small and that the differences between bright and dull are on the 
whole only seven per cent, of the difference between the extremes 
of motor ability for the same age (calling that difference seven 
times the mean variation, which is approximately correct). 

TABLE XIV. 

The Relationship between Mental, Ability (as Estimated by a Teacheb) 

AND THE Rate of Tapping. 

No. 





Number of Taps. 




Absolute DiflFerences. 


DiflF. in Terms of Varia'ty. 


ofCai 




Bright. 


Aver. 


Dull. 


Bright-Aver. 


Bright-Dull, 


. Bright-Aver. 


Bright-Dull. 


Studi( 


6 


22.1 


22.3 


21.5 


— .2 


.6 


—.09 


.28 


91 


7 


25.2 


25.3 


21.2 


— .1 


4.0 


—.04 


1.48 


96 


8 


26.0 


26.5 


24.0 


— .5 


2.0 


—.20 


.82 


93 


9 


27.0 


26.9 


26.0 


.1 


.7 


.04 


.28 


100 


10 


27.1 


28.5 


27.5 


—1.4 


— .4 


—.45 


— .13 


108 


11 


29.0 


27.4 


27.4 


1.6 


1.6 


.50 


.50 


97 


12 


29.7 


30.0 


27.8 


— .3 


1.9 


—.10 


.62 


111 


13 


31.0 


30.3 


29.0 


.7 


2.0 


.21 


.61 


101 


14 


32.0 


31.0 


28.8 


1.0 


3.2 


.26 


1.16 


92 


15 


33.4 


33.2 


31.0 


.2 


2.4 


.08 


.91 


95 


16 


34.0 


33.8 


33.2 


1.2 


1.8 


.39 


.58 


92 


17 


34.0 


34.0 


34.6 


.0 


— .6 


.00 


— .23 


100 


18 


36.1 


35.1 


35.0 


1.0 


1.1 


.36 


.40 


100 


19 


36.2 


36.3 


36.0 


— .1 


.2 


—.03 


.06 


81 



All ages together -1-.07 -|- .52 

I found no correlation direct or inverse between school 
marks and the accuracy of movement, though my cases were too 
few to make the conclusion sure. I judge from a few measure- 
ments that in the case of adults a direct correlation, but less than 
.05 in amount, does exist. Havelock Ellis claims, however, that 
bodily awkwardness is commoner among men of very superior 
intellects than among common men.* 

Even this inadequate study of the relations of bodily condi- 
tions to mental ability shows some things clearly. 

The dependence of mental ability upon the general bodily con- 
ditions that we have reviewed is surely slight. The most gifted 
five per cent, and the least gifted five per cent, mentally are not 
much unlike in stature, strength, health, muscular control or phys- 

* Popular Science Monthly, Vol. 59, p. 272. 



RELATIONSHIPS OF ilESTAL AND PHYSICAL TRAITS 151 

ical dexterity. I am sure that we could pick out mentally gifted 
men or children more successfully by ten minutes' observation of 
their facial expression, manners and opinions than by a day's 
work in measuring any combination of anatomical traits or motor 
activities. 

The efficient action of those parts of the brain wliicli are re- 
lated to the intellectual life is to a large extent independent of 
the station of the individual with respect to the efficiency of other 
physiological functions. 

The expectation that the improvement of general bodily wel- 
fare or of muscular dexterity will produce an improvement in 
mental efficiency is justifiable only if we expect it in slight amount 
and in a limited number of cases. If a person ranks — 10 in in- 
tellect and is a physical weakling, we may raise him to — 9 or 
— 8 by gymnastics and manual training, but we will never get 
him far above his original station. Again if a thousand dull 
boys are given physical and motor training the majority of them, 
I fancy a very large majority, will be as dull after as before. 
Such admirable features of school training do not need the sup^ 
port of any absurd exaggerations of their effects on mental traits. 



CHAPTER XIV. 

BEOADEK STUDIES OF HUMAN NATURE. 

Within the last fifteen years there have been, in connection 
with the so-called child-study movement, a number of studies of 
concrete facts of human nature which follow a fairly definite 
type, though it is hard to find a single phrase by which to describe 
them. They are attempts to answer such questions as : " What 
are the attitudes of human beings toward water, or toward trees, 
or toward dolls, or toward punishment? What are the actual 
facts about the influence of teachers, parents, books ? Wliat is the 
rationale of human fears, of human affection, of children's inter- 
ests ? " They are characterized by the effort to reach generally 
valid conclusions from a wholesale collection of individual ex- 
periences. They commonly start with a list of general topics for 
study rather than with definite questions to be solved. Their 
material is almost without exception not direct observation, but 
either the answers written in reply to a printed list of questions 
or the papers written by school children as a school exercise in 
response to some question or suggestion. They have purported 
to be important to educational science on some such basis as this : 
Any true account of the real life of men and women, boys and 
girls will help us to control those lives in accord with our educa- 
tional ideals, and will give suggestions of forces in human nature 
at the service of educational endeavor which have been hitherto 
neglected. 

If the reader has read or will read any half dozen of the fol- 
lowing articles he will have a concrete idea of this type of work 
that will be a better introduction to the discussion to follow than 
any further description. 

*A Study of Peculiar and Exceptional Children,' Pedagogical Seminary, 
Vol. IV., pp. 3-60. 

' A Study of Dolls,' Pedagogical Seminary, Vol. IV., pp. 129-175. 
'Teasing and Bullying,' Pedagogical Seminary, Vol. IV., pp. 336-371. 
'A Study in Moral Education,' Pedagogical Seminary, Vol. V., pp. 5-40. 
' Some Mental Automatisms,' Pedagogical Seminary, Vol. V., pp. 41-60. 

152 



BROADER STUDIES OF HUMAN NATURE 153 

'The Psychology and Pedagogy of Adolescence,' Pedaqogical Seminary, 
Vol. v., pp. 61-128. 

'Manifesting the Instinct for Certainty,' Pedagogical Seminary, Vul. \'., 
pp. 313-380. 

'Reverie,' Pedagogical Seminary, Vol. V., pp. 445-474. 

'The Only Child in the Family,' Pedagogical Seminary, Vol. V., pp. 475- 
496. 

'A Genetic Study of Immortality,' Pedagogical Seminary, Vol. VI., pp. 
267-313. 

'The Psychology of Ownership,' Pedagogical Seminary, Vol. VI., pp. 421- 
470. 

' Children's Ideals,' Pedagogical Seminary, Vol. VII., pp. 3-12. 

'Children's Interest in the Bible,' Pedagogical Seminary, Vol. VII., pp. 
151-178. 

'The Collecting Instinct,' Pedagogical Seminary, Vol. VII., pp. 179-207. 

'A Study of the Teacher's Influence,' Pedagogical Seminary, Vol. VII., 
pp. 492-525. 

'Old Age and Death,' American Journal of Psychology, Vol. Vlll., pp. 
67-122. 

'A Study of Fears,' American Journal of Psychology, Vol. VIII., pp. 
147-249. 

'A Study of Conversion,' America7i Journal of Psychology, Vol. VIII., 
pp. 268-308. 

'A Study of Puzzles,' American Journal of Psychology, Vol. VTTI,, pp. 
431-493. 

' Some Aspects of the Early Sense of Self,' American Journal of J'sy- 
chology, Vol. IX., pp. 351-395. 

' The Institutional Activities of American Children,' American Journal 
of Psychology, Vol. IX., pp. 425-447. 

For the sake of readers to whom these articles are not readily 
accessible I will quote from one of the best devised and most 
instructive of these studies* at sufficient length to give a rough 
idea of the method in its more successful application. 

Some of the questions asked were : 

Growth generally. When was growlli in height or weight grcntcstT 
Was this period of growth attended by better or deranged health? Give any 
details, as to how much, where, how long, etc. 

General Health, then and now. If imperfect, how, respecting oyc*, 
nerves, head, stomach, etc.? Was sleep or dreani.s, or appetite for food 
affected ? 

Changes of Form and Feature. Did chin, nose, clu^'k bono, brow, rhoftt, 
hair, and other features clinnge, and how? Was there a dilTcrcnt facial 
expression? New resemblances? To whom? 

Senses and Thought. Are the senHcs keener, wider ranged? More en- 

* Lancaster's ' Psycholopj' and Pedagogj' of Adolescence,' Pcdagoginl 
Seminqry, Vol. V., pp. 01-128. 



154 EDUCATIONAL PSYCHOLOGY 

grossing? I& there a change from sense to thought; from the present to 
the future; the near to the far? What new ideals, abstract or personal? 

Language. Was it harder or easier to express one's self, and was there 
a dumb, bound feeling? Was truth-telling harder or easier? 

Future. Were careers, plans, vocations, trades, etc., dwelt upon? 

Home. Did the attractiveness of home diminish, and was there a ten- 
dency to be out, go far away, strike out for self, seek new associations and 
friends? Should home be left part of the time? 

Parents and Family. Did parental iniiuence decline? How differently 
were father and mother, brother, sister, and other relatives regarded? Pa- 
rental authority, punishments? 

School. Was there a disposition to leave school, change studies or 
teachers, defy authority, or to feel more deeply studies, punishments and 
discipline ? 

The author gives in every case of importance samples of the 
replies. For instance, from the replies to the question about ca- 
reers, plans, vocations, etc., he quotes the following: 

F., 18. As a child I dreamed much of the future. Wanted to be a 
musician, elocutionist, artist, milliner, bookkeeper, dressmaker and a school 
teacher. Have often desired to be as beautiful in character as Christ him- 
self. 

F., 24. One of the greatest pleasures of my life has been to make plans 
and map out an ideal career. 

F., 20. Planned to teach in my early childhood. At 13 I began to de- 
clare it, and after much discussion my wish was granted, and I began to pre- 
pare for it, to my great delight. 

M., 50. Nothing is more intense and vivid than my plans for the future. 
One scene. A high hill with bald summit. Had been blamed for something 
and went to that peak. Alone there I had a very deep and never-to-be- 
forgotten experience. I paced back and forth and said : ' Now I will, I 
WILL, make people like me, and / WILL do something in the world.' I 
called everything to witness my vow. 

F., 23. My plans for the future were all for literary fame. School 
aroused my ambition and for three successive years I took essay prizes. 

M., 18. I look to the future. Think of myself as teaching, reading 
law, at the bar, in legislature, an active speaker always taking the side of 
right and denouncing wrong. I have had many ideals, one to be a minister. 

F., 19. I often think of the future and wonder what it has in store 
for me. I sometimes wish that ten years would pass in a night. 

M., 19. Plaimed his future and painted it with the tints of the sea- 
shell. 

F., 19. In mind I have planned the first day of school and gone through 
it many, many times. At one time I wanted to be a trained nurse. I 
pictured myself among the patients and how I would act in an operation. 
Then how I would study abroad and get a fine position. 



BROADER STUDIES OF HUMAN NATURE 155 

He also discusses each topic in a general way. The follow- 
ing is his presentation of facts and conclusions, with reference to 
the attitude of adolescents toward home, parents and family : 

403 answered the question regarding home. 253 — 153 M., 100 F., had a 
desire to leave home and strike out for themselves or found home less at- 
tractive. 150 — 29 M., 121 F., had no desire to loave home. 

107 thought that home should be left a part of the time, 20 thought 
it should not. 

As to parents and family, 281 replied. 99-33 M., GO F., said parental 
influence did decline, while 181 — 35 M., 146 F., found their parents just as 
dear and obeyed them as readily as in childhood. 

100-32 M., 68 F., felt a disposition to leave school or did leave for a 
while during this period. 192 — 98 M., 94 F., had no such feeling. 

It must be borne in mind that these returns were mostly from normal 
school, high school, academy and college students, a majority of whom were 
away from home when they wrote. 

75 — 34 M., 41 F., say that punishment was felt much more deeply. 
18 — 9 M., 9 F., experienced no change. 

This gives a very true picture of the feelings of young people toward home, 
school, and authority at this period of life, because the answers were given 
under conditions allowing free speech and favoring home, parents and school. 
It is a very forcible illustration of the fact that a boy or girl from 12 to 18 
is fully conscious of personality and the rights of individual recognition. 

This feeling that home is shut in and the desire to get away and travel, 
to see for one's self and form new associations, is an instinct as old as the 
race and common to all animal life. It is like the migratorj* instinct of 
birds. It may spring up suddenly with the most obedient and well-bred 
children. It is not a sign of degeneration or of less love for the home or 
parents. It is often associated with the most intense love of homo and family. 

The feeling is strongest at 16 to 18 or about the time of the final ap- 
proach to maturity. 

The sudden feeling of rebellion against authority, which often surprises 
the child as much as the parent, is another instinctive babit of the race. 
These crop out in the best children, sometimes with a violence that shocks 
everybody. 

It is not necessarily a bad sign, unless frequently repeated. The desire 
to leave school, together with the desire to leave home, is a true and natural 
impulse to adjust himself to the life which he is already living in his imagina- 
tion in company with his ideals. 

Sympathy, not punishment, is the proper corrective. 

Studies of this type have not been quoted in connect inn witli 
the topics discussed in our previous chapters because they are in 
many cases unrelated to those chosen for treatment in this lx)ok 
and because when the topics are appropriate the fact.^ they claimed 
to present have hoou stated in terms with which quantitative 



156 EDUCATIONAL PSYCHOLOGY 

science can not deal. Partly to explain this apparent neglect of 
a large number of researches in educational psychology and 
partly to assist the reader to a just estimate of their value, we 
must now answer certain questions. 

1. Can the loves and hates, fears, interests, ideals, habits, 
notions and opinions, etc., of human beings, the influence of books, 
teachers, religions, games, toys, etc., be made the objects of suc- 
cessful scientific investigation ? 

2. What profit will accrue to educational science from such 
investigations ? 

3. To what extent are the methods that have been employed 
in these studies reliable ? 

4. To what extent are their conclusions reliable ? 

5. To what extent are their conclusions important? 

1. There is no reason why we can not list and describe and 
estimate quantitatively and relate to any other set of facts, any 
features of human life. Affection for dolls can be studied as 
scientifically as reaction-time or rate of movement, though not as 
easily. Those who deny the ability of the statistician to measure 
any facts of mental life are ignorant or forgetful of the theory 
of measurement by relative position used by Galton years ago. 
The complex nature and the variability of these facts make sci- 
entific work hard but not impossible. 

2. We can not tell until the investigations have been made and 
can not tell fully until the complete course of science and life 
has been run. The action of knowledge on practise is compli- 
cated, indirect and often long deferred. But either directly or 
through its helpful influence toward some other discovery, either 
soon or after it is supplemented by some other fact, any new bit 
of knowledge seems sure somehow to economize human effort and 
increase human control. The faith in science which urges us 
to collect butterflies and mastodons, to spend vast sums to observe 
eclipses, to devote years to Latin inscriptions and lives to the 
vagaries of primitive religions, ought to justify the study of even 
minor features of human minds and characters. 

The third question can not be answered so summarily. And 
in the nature of the case no single absolute answer will fit all the 
different studies. A method useful in one case may be quite use- 



BROADER STUDIES OF HUMAN NATURE 157 

less in another. Some general principlL-s, however, are sure and 
may guide us in estimating the worth of the method in anv single 
case. First of all, the ignorance of a thousand people is no bet- 
ter than that of one ; truth can not he manufactured from constant 
errors by getting a great number of them. For instance, from 
scoring up replies to the question, ' When did your child first 
reason?' we do not necessarily learn anything about the date of 
appearance of reasoning, but only about opinions of people as to 
that date. From scoring up replies to the suggestion, ' Descrilx3 
some miser of your acquaintance,' we attain knowledge not of 
misers, but of what our correspondents notice or think they have 
noticed in some obvious types of miserliness. No research can 
ever attain a reliability beyond that possessed by the data with 
which it starts. And the first duty of any study of individual 
responses to questions or suggestions is to measure their relia- 
bility as measures of the trait in question. Adults even so well 
trained as college seniors and even in the simplest matters of 
present objective fact such as are involved in the questions, 
' How tall are you ?' ' What is the circumference of your sis- 
ter's head ?' make gross errors. The errors increase in number 
and amount when the report requires memory ; increase f urtlior 
when the fact is a report of subjective condition, and multijdy like 
bacilli when it involves the consideration of the general drift of 
a series of experiences. Again, no matter how clearly the ques- 
tion is put some individuals misunderstand it. Finally any 
question acts as a suggestion and with uncritical minds will s\irely 
produce affirmative answers. 

There are means of avoiding many of these errors and recog- 
nizing and allowing for many of the others. But these means 
have not been used in the investigations un<ler discussion. We 
can feel but little confidence in a method wliidi ]iretends to secure 
truth from a collection of the answers of yimng people in normal 
schools to such questions as the following: 

Have liberalizing theological opinions made you better or worse, and 
how? Ped. Sent., Vol. V., p. 8. 

What is your own lompornmont ? Ih'ul., j). 1.3. 

TIas your Ijclicf in inunorlality liorn nn unfoUlinont of your nature or 
is it the result of parental inlluencc, acri|>i iiriil teaching, observation of 



158 EDUCATIONAL PSYCHOLOGY 

natural phenomena, loss of friends in death, or your own inability to con- 
ceive your existence as coming to an end? Ped. Sem., Vol. VI., p. 287. 

Wliat effect has [sic] a new overcoat, high hat, high heels, ribbons, 
plumes, bright buttoned uniforms, articles of jewelry, buttons, badges, etc., 
upon the self-confidence, self-assertiveness and personality of the owner? Ihid., 
p. 430. 

What force and motive led you to seek a higher and better life? Am. J. 
of Psy., Vol. VIII., p. 269. 

What is the educational value of puzzles? Ibid., p. 448. 

Is the puzzle-loving mind or state like that of the scientific man bent on 
solving problems of laboratory or study? Ibid., p. 447. 

What do you know of beggars? Their habits, laws, customs? Ped. 
Sem., Vol. VI., p. 431. 

What studies have best developed your memory? Am. J. of Psy., Vol. 
X., p. 229. 

Can blood pressure be tested? Am. J. of Psy., Vol. X., p. 529. 

In the second place the facts reported by individuals who 
respond to sets of printed questions need not and commonly will 
not represent the true state of affairs in the group ostensibly 
studied. Psychological questionnaires are commonly sent to 
' those interested ' or to psychology classes in normal schools and 
answered by only a limited number of those who receive them, 
namely by the individuals to whom the questions especially ap- 
peal and who have something to report or by those who answer them 
as an academic study. The replies thus represent an extremely 
partial sampling of people in general. Moreover, of those who 
do reply either from zeal or as a matter of school work, only a 
small number answer all the questions. In the case of any one 
question then we get answers from the few, probably from those 
who have a positive or emphatic answer. We can be sure before- 
hand that these replies will not give a representation of the facts 
that really exist in the total group. Here again it would be 
possible to correct the bias of the replies from such a selected 
group by the study of fifty or a hundred individuals chosen quite 
at random. But this has never been done. 

For instance, in the case of the study already quoted there 
were received about 500 replies from classes in normal schools, 
colleges and academies and about 300 replies from individuals. 
The group of students certainly do not represent the general popu- 
lation. How the 300 were selected we are not told, nor what 
proportion they were of the total number to whom the questions 



BROADER STUDIES OF U LAI AX NATURE 109 

were sent. There was not a single question asked in the list that 
was answered by all of the T87^'- whose replies are the basis of the 
article. Out of the total number for each sex the following num- 
bers (in percentages) replied to the different questions which the 

author discusses. 

TABLE XV. 

Each number is the percentage that tlie number of answers to some 
one question was to the number replying to the questions as a whole. 



ilales. 


Females. 


Mules. 


Females. 


17.0 


28.0 


11.4 


11.7 


40.2 


48.9 


29.3 


41.5 


13.2 


35.5 


15.0 


22.8 


13.2 


14.8 


40.9 


77.1 


10.3 


17.5 


97.4 


97.3 


19.9 


35.2 


85.6 


68.6 


23.6 


20.7 


105.0 


77.1 


29.1 . 


55.4 


63.1 


63.2 


72.7 


48.0 


74.2 


54.7 


53.4 


49.6 


81.2 


64.8 


19.9 


47.5 


72.4 


61.9 


24.6 


19.3 


44.9 


51.1 


34.7 


63.9 







These percentages range from 10.3 to 105 for males and from 
11.7 to 97.3 for females. The averages are: Males, 44; fe- 
males, 47. The variabilities {A. D.) are 24.7 and 16.8. There 
are marked sex differences in the number replying, the extremes 
being, women 6Q per cent, as many replies as men and 269 per 
cent, as many. These facts demonstrate that chance is not the 
cause for tlie number of replies and failures to reply and that 
some real principle or principles of selection do determine them. 

It is incredible that the 85 per cent, of men who do not 
answer at all the question, ' Were there impulses to reform self, 
others, religion, state, society, etc. ? ' had the same feelings about 
the matter at adolescence as the 15 per cent, wlio did answer, and 

* The autlior docs not even take pains to make this number dear, in 
one place we read, * 827 (replies) have been received . . . these answers 
have been grouped and condensed and the results will be given' (p. 07). ami 
two pages later we read: '341 males and 44(> females answered jiart or all 
of it' (the syllabus of questions). My percentages are based on tliis .second 
statement, to avoid any possibilily of injustice. From the fact that one per- 
centage thus computed is 105, I regard it as likely that the 827 is correct 
and Ibal my percentages are even too large by .'> per cent. 



160 EDUCATIONAL PSYCHOLOGY 

of whom practically all (approximately 97 per cent.) say, 'Yes.' 
The probability indeed is that of the 85 per cent, few or none 
had felt such impulses to any noticeable extent and that the real 
affirmatives amongst the 341 males replying to the question should 
be reckoned at from 15 to 20 per cent. This percentage calculated 
from the interested and from academic students would be further 
reduced if mechanics, day laborers, clerks and the rest of the 
youth of the land were studied. The figures for the girls are of 
the same order of magnitude. Yet the author says : ' This feel- 
ing ... is very characteristic of adolescence.' 

I have attempted to make an estimate of the partiality of the 
sampling in these studies as a whole by computing from all such 
articles in the volumes of the American Journal of Psychology 
and Pedagogical Seminary from 1896 to 1900, the proportion of 
individuals replying to individuals questioned, and the proportion 
that the answers to each question are of the individuals replying 
to the questionnaire as a whole. Such an estimate can not be made 
because the ignorance or neglect of the fallacy of selection has 
been so great that only one article in the eight volumes gives 
clearly the number of individuals questioned, and none gives full 
information regarding the number of replies received to each 
detailed question. Some do not even give the number of indi- 
viduals replying to the questions as a whole. In the one case 
where the number of those questioned is given, less than one 
sixth replied (15.67 per cent.). 

In the third place the use of replies to questions and of school 
compositions involves the exercise of much personal opinion as to 
the meaning of each report. Different individuals will differ 
somewhat even in their measurement of a line, will differ mark- 
edly in their estimate of the intelligence shown in any test, and 
would certainly differ in their rating of the replies to such com- 
plex and subtle questions as many of those on pages 157-8, or 
of the school compositions on the topics quoted. The statements 
finally used to inspire conclusions are thus a compound of the 
actual reports and the subjective bias of the compiler. This 
could be avoided by the simple expedient of having several un- 
biased clerks go over the papers. By combining their opinions 
one could eliminate personal idiosyncrasies of judgment. This 
has not been done. 



BROADER STUDIES OF UVilAy yATURE IGl 

Tn the fourth phice the progress from a set of statements 
about individuals to a statement about a group including them 
is by no means a matter of simple addition. There is a fairly 
complex science of mental statistics which has been found neces- 
sary to keep students out of pitfalls. Failure to take advantage 
of it is always a suspicious characteristic in any metliod of study- 
ing groups. 

Conclusions about the facts studied onlv indirectlv through 
the reports of incompetent observers, in the case of individuals 
representing a partial and undefined selection, compiled by a 
single and possibly prejudiced student without the knowledge of 
the technique and logic of statistics, are utterly unreliable. They 
may be true ; they may be false ; they arc probably a mixture. 
But we can not know how true or false they are. 

Our last question (To what extent are the conclusions reached 
in these investigations important?) should properly be replaced 
by as many separate questions as there have been separate con- 
clusions. Still some statements may be made that will apply 
fairly well to the bulk of these studies. First it is questionable 
whether we ought nowadays to pay any attention in our theoriz- 
ing about education to conclusions that are utterly uuroliable. 
There would be a great saving of time and a desirable moral elTect 
if we restricted ourselves to facts of measured reliability. From 
this point of view, the importance of these studies would seem to 
shrink to small proportions. However, their conclusions are at 
least the opinions of thoughtful and experienced students who 
have reviewed a large array of data, and in so far as tlie intel- 
lectual virtues of the student outweigh the vices of the method 
these conclusions are superior to habitual opinions. 

A second consideration is worthy of note. ^lere invcntorica 
of traits are of relatively little importance in comparison with 
knowledge of their relationships among tliemsclves and to other 
things. Thus information about 1,000 people with rosjvct to one 
trait is of far less importance than information about 100 traita 
in each of 10 individuals. Human nature is so complex that 
we rarely learn much about any one aspect of it if that is disso- 
ciated from all the rest, or studied without reference to all the 
factors of original nature and environment whidi arc its cau.'»cs. 



162 EDUCATIONAL PSYCHOLOGY 

The failure to connect the facts studied with the total lives from 
which they are tiny excerpts and to seek the facts which will 
elucidate causal action in mental life is perhaps the one charac- 
teristic of these studies which detracts the most from the im- 
portance of their conclusions. 

On the whole, then, although their purpose — to deal scientific- 
ally with the rich content of human nature and so secure a basis 
for educational control — is in every way laudable, these studies 
have not sufficiently realized it to be accepted as desirable exam- 
ples of educational science. It is to be hoped that if an equal 
amount of genius and effort is spent in the next decade upon sim- 
ilar problems, the work will be done by means of direct expert 
observation of representative cases with reference to all the fac- 
tors involved, and with a moderate amount of statistical care. 



CIlAPTEIl XV. 

THE PROBLEM OF EDUCATION AS A SCIENCE. 

A THEORY of education must decide two questions: (1) What 
ought people to be ? (2) IIow sliall we change them from what 
they are to what they ought to be ? One's answer to the first 
question, the question of the aim of education, will be given in 
accord with his conceptions of ultimate values and will be judged 
not by facts but by ideals. The studies which have been made 
in this book have nothing to do with it. 

They are relevant to the second question of the ways and 
means of education. To know the original natures of the beings 
to be educated and to know the influence of the forces of nature, 
human lives and all the paraphernalia of civilization upon these 
original natures is to know how to control their education in the 
interest of the aim we have chosen. 

It is not the purpose of this book to criticize existing theories 
or to attempt the construction of a new one. For there is no 
chance for any simple general theory. The work of education 
is to work changes in countless individuals all different by orig- 
inal nature. These changes are again infinite in variety. Eacli 
bit of knowledge, each interest, each habit, each power, each ideal 
has its own best means of attainment. Multiply the numl>er of 
different changes desired by the number of different original 
natures to be changed and the resulting number of concrete prob- 
lems will measure the number of separate concrete precepts wliich 
the art of education mnst include. For this boy in this informa- 
tion, — leave him alone. For this girl in tlmt interest, — example. 
For this man in that habit, — beat him with rods. For this power 
in that youth, — this study. For this ideal in that race, — give up 
the task; nature has denied it to them. Such is the variety of 
recommendations whirli we know must needs exist. The true 
general ihoorj' must be the helpless one tliat there can Ix; no 
gener;il tlioory, or be made uji of suHi pxtremoly vague ooncln- 
sions as the featuros mTuinon fc all human natures and the rlmngp;* 



164 EDUCATIONAL PSYCHOLOGY 

everywhere desirable allow. Sucli conclusions are on a level for 
helpfulness and illumination with the inane tautologies of hygiene 
books. " Good air, nutritious food and proper exercise are sure 
to assist health." 

A true educational science must be inductive, must be made 
Up from the study of the particular facts in answer to thousands 
of different questions. 

It is the vice or the misfortune of thinkers about education 
to have chosen the methods of philosophy or of popular thought 
instead of those of science. We ruminate over the ideas of Pesta- 
ilozzi or Herbart or Froebel as if writing a book a hundred years 
ago proved a man inspired. We discuss the outpourings of suc- 
cessful college presidents as if devising a public address was a 
voyage of discovery for truth, and the newspaper type of argu- 
ment its crucial test. We are like chemists who should quarrel 
■over the views of Paracelsus or Arnauld of Villeneuve and debate 
jabout the latest articles by Maria Parloa. ' In education everything 
:is said but nothing proved. There is a plentiful lack of knowledge 
while opinions more and more abound. They are often very good 
of their kind but they are not science. 

The science of education when it develops will like other sci- 
ences rest upon direct observations of and experiments on the 
influence of educational institutions and methods made and re- 
ported with quantitative precision. Since groups of variable 
'facts will be the material it studies, statistics will everywhere be 
its handmaid. The chief duty of serious students of the theory 
of education to-day is to form the habit of inductive study and 
learn the logic of statistics. Long after every statement about 
mental growth made in this book has been superseded by a truer 
one the method which it tries to illustrate will still be profitable 
and the ideals of accuracy and honesty in statistical procedure by 
•which I hope it has been guided will still be honored. We conquer 
dhe facts of nature when we observe and experiment upon them. 
'When we measure them we have made them our servants. A little 
statistical insight trains them for invaluable work. 



APPENDIX T. 

ExpLANATony Index of the Less Common Tests Mentioned in the 1*ext. 

A test (see page 4). 

at test (see page 9). 

Alphabet test. Writinj; letters as rapidly as possible, each letter to be 
the letter precciiinf,' in the alphabet a given letter. The letters given were 
f, k, s, p, \v, 1, e, r, d. o, v, j, n, t, h. 

Association time or Q association. The time taken to call up and write 
a mental associate for each of ten words, the words being printed on a blank. 

Association time (as used by Johnson). A key word was given and 
thirty seconds were allowed for saying the words which came to the mind, each 
word being written by the experimenter as soon as spoken. The number of 
seconds divided by the numlier of words written gives the average association 
time. The key words were; house, tree, chair, ship, clock. Fourth of July.* 

Genus-species test, ^^"^iting as rapidly as possible a word meaning some 
species of the genus meant by a given word. 

Geometrical forms. Tests in marking circles, hexagons or some simple 
figure on a blank printed with a chance mixture of a score of dilTerent 
geometrical figures. 

Letter combinations. Tests like the a-t test or e-r test. 

Maze test. The amount done and the touches made in an attempt to 
draw a line within a pathway 2 millimeters wide in a figure like that shown 
(reduced to i) in figure 48. In another figure the pathway was curve<l. 

Memory of related words. Memory of such series as — school, teacher, 
book, desk, pen, read, write, add, spell, word. 

Memory of unrelated words. Memory of such series as — red, dog, buy, 
day, sick, never. 

Misspelled word test. The number of misspelled words marked in a 
j^ven time on a blank printed as follows: 

Mark Evert Word that is not Spelled Corbectlt. 

1. On the 3d of September, 1832, inteligencc was broght to the collecter 
of Tinnevclly that som wildd eliphants had appeare<l in the neighborhod. 
A hunting party was imediately formed, and a large number of nattivc 
hunters were engaged. We left the tents, on horshack. at half post scvin 
o'clock in the juorniing and rode thre miles to an open spotc. Hanked on one 
sid bye Rice fields, and on the other l>y a jungle. 

2. After waiting som time, Captain U and my.Hplf walked acros the 

rice-fields to the shad of a tree. There we herd the trumpett ol an elephant; 
we reshed acros the rice fiebls up to our knes in nuul. but all in vj»i\i, thogh 
we came upon the trak of ouc of the animcl.H, and then ran five or aix hundrcdd 
yards iutoo the jungle. 

* An abstract from the account of the test given by Johnson, who uned 
it, on page 282 of Vol. IIL of the I'ciUi'jnrficitl Seminary. 

105 



166 EDUCATIONAL PSYCHOLOGY 

3. After varius false allarms, aud vane endevors to discuvor the obgects 
of our chace, the colector went into the jungle, and Captin B and my- 
self into bed of the stream' where we had sen the traks; and here it wag 
evedent the elaphents had passed to and fro. Disapointed and impasient, we 
allmost determened to giv up the chace and go home; but shots fird just 
before us reanimated us, aud we proceded, and found the eollecter had 
just firred twicce. 

4. Of we went throuh forest, over ravin, and through strems, till att last, 
at the top of the ravine, the elephants were seen. This was a momant of 
excitment! We wer all scatered. The collector had taken the midle path; 

Captain B , some huntsmen, and myself took to the feft; and the other 

himters scrabled down that to the rite. At this momunt I did not see enything 
but after advanceing a few yards, the hugh hed ef an elephunt shaking abuve 
the jungle, withen ten yards of us, burst sudenly upon my view. 

5. Captain B ande a hunter justt befor me; we al fired at the 

same moment, and in so dirrect a line that the percussion-cap of my gun hitt 
the hunter, whome I thougt at first I had shoot. This accident, thogh it 
pruved slight, troubled me a litle. The grate excitement ocasioned by seeing, 
for the first tim, a wild best at liberty and in a state of natur, product a 
sensation of hop and fear that was intens. 

Naming colors. The individual measured was required to give out loud 
the series of color names corresponding to a series of small squares of colored 
paper arranged upon a sheet of paper. 

Opposites tests. Writing as rapidly as possible the opposites of a given 
set of words. The given words were in the case of the easy opposites — good, 
outside, quick, tall, big, loud, white, light, happy, false, like, rich, sick, glad, 
thin, empty, war, many, above, friend. 

Part-whole test. Writing as rapidly as possible a word meaning the 
whole of which the thing meant by a given word was a part. 

Parts of speech. Marking nouns, verbs or some other parts of speech 
wherever they occurred in a page of simple English prose. 

r-e test. This was the same as a-t test except that the words to be 
marked were those containing r and e. 

Word test. To write words containing certain given letters (e. g. write 
a word of six letters containing 1 and o ) . 

Controlled thinking with word relationships. The opposites, genus-species 
and part-whole tests and their like. 



APPENDIX 11. 

Explanatory Index of Common Meastjees. 

Measurements of General Tendency. 

the sum of the individual measures 

The average = ~r- r j 

the number of cases. 

The medians the measure above and below which an equal number of 

the individual measures lie. 

The mode = the most common of the individual measures. 



APPESDIX 167 

Measures of Variability. 

The average deviation (A. I). )^thc average (arithmetical) of the 
deviations of the individual measures from their average. 

The probable error of a distribvition (P. E.) = the amount of difference 
from the average such that TjO per cent, of all the individual measures lie 
between Av.— P. E. and Av.+ P. E. 

The standard deviation (it) of a distribution ^ the square root of the 
average of the squares of the deviations of the individual measures from 
their average. 

The cocnicicnt of variability = some measure of variability divided by 
some measure of the general tendency of the ability; ». c, any one of the 
following : 

Average deviation divided by average. 
" " " median. 

" " " mode. 

Probable error of a distribution divided by average. 

median, 
mode. 

Standard deviation divided by average. 

median. 
" " " mode. 

Measurements of Relationship. 

The coelficient of correlation (r). Let x„ x„ x„ x„ x,, etc., be the devia- 
tions from the average of one series of measures; let j/i, !/i. .Vi, «/.. .Vj. etc., be 
the corresponding deviations from their average of the second series. Let d, 
be the standard deviation of the first series and a, be the standard deviation 
of the second series. Let n be the number of pairs. Then 

_8um of z,y,, x^„ t^„ etc 



Measurements of Reliability (or more properly of unreliability). 

These are all measures of the likelihood of a certain difference between 
the true result (the one that would obtain in the case of our measurement 
if we had an infinite numlx:r of measures) and the one actually obtained from 
the few measures we have actually made. The measure will thus involve 
a statement of an amount of difference and of the likeliliood of unlikelihood 
of the existence of one as great or greater than it. Sample formulir are the 
following: 

The chances arc a bit over 2 to 1 that the true average will not deviate 
from the obtained average by more than the standard deviation of the distri- 
bution in question divided by the square root of the numl>or of rases studied. 
The chances are a bit over 2 to 1 that the tnie variability will not differ 
from the obtained variability by more than the standard deviation of the distri- 
bution in question divided by the sqtiare root of twice the numl>er of case*. 
The rhances are 1 to 1 that the tnie relationship will not differ from the 

obtained relationship by over 

I •■ 
.071'. 

Vn(l + H) 



168 



EDUCATIONAL PSYCHOLOGY 



The unreliability of a difference between two things equals the square 
root of the sum of the squares of the unreliabilities of the two things. 

TABLE A. 

TABLE OF VALUES OF THE NORMAL PROBABILITY INTEGRAL CORRESPONDING TO 

X 
VALUES OF — : OB THE FRACTION OF THE AREA OF THE CURVE BE- 


X X 

TWEEN THE LIMITS AND -I OS AND — — . 

a a 

Total a/rea of curve assumed to he 10.000. 
a? = deviation from mean. 
c = standard deviation. 



z 

a- 





1 


2 


3 


4 


5 


6 


7 


8 


9 


A 


0.0 


0000 


0040 


0080 


0120 


0160 


0200 


0239 


0279 


0319 


0359 


40 


0.1 


0399 


0438 


0478 


0517 


0557 


0597 


0636 


0676 


0715 


0754 


40 


0.2 


0793 


0832 


0871 


0910 


0948 


0987 


1026 


1064 


1103 


1141 


39 


0.3 


1179 


1217 


1255 


1293 


1330 


1368 


1406 


1443 


1480 


1517 


38 


0.4 


1554 


1591 


1628 


1664 


1700 


1737 


1773 


1808 


1844 


1879 


36 


0.5 


1915 


1950 


1985 


2020 


2054 


2089 


2124 


2157 


2191 


2225 


34 


0.6 


2258 


2291 


2324 


2357 


2389 


2422 


2454 


2486 


2518 


2549 


32 


0.7 


2581 


2612 


2643 


2672 


2704 


2734 


2764 


2794 


2823 


2853 


30 


0.8 


2882 


2910 


2939 


2967 


2995 


3023 


3051 


3078 


3106 


3133 


28 


0.9 


3160 


3186 


3212 


3238 


3264 


3290 


3315 


3340 


3365 


3389 


26 


1.0 


3414 


3438 


3461 


3485 


3509 


3532 


3555 


3577 


3600 


3622 


23 


1.1 


3644 


3665 


3686 


3708 


3729 


3750 


3770 


3791 


3811 


3830 


21 


1.2 


3850 


3869 


3888 


3906 


3925 


3944 


3962 


3980 


3997 


4015 


19 


1.3 


4032 


4049 


4066 


4083 


4099 


4115 


4132 


4147 


4162 


4178 


17 


1.4 


4193 


4208 


4222 


4247 


4251 


4265 


4279 


4292 


4306 


4319 


14 


1.5 


4332 


4345 


4358 


4370 


4383 


4395 


4406 


4418 


4429 


4441 


12 


1.6 


4452 


4463 


4474 


4485 


4496 


4506 


4516 


4526 


4536 


4545 


10 


1.7 


4554 


4564 


4573 


4582 


4591 


4600 


4608 


4617 


4625 


4633 


9 


1.8 


4641 


4648 


4656 


4664 


4671 


4678 


4686 


4693 


4700 


4706 


7 


1.9 


4713 


4720 


4726 


4732 


4738 


4744 


4750 


4756 


4762 


4767 


6 


2.0 


4773 


4778 


4783 


4788 


4794 


4799 


4804 


4808 


4813 


4817 


5 


2.1 


4822 


4826 


4830 


4834 


4838 


4842 


4846 


4850 


4854 


4858 


4 


2.2 


4861 


4865 


4868 


4872 


4875 


4878 


4881 


4884 


4887 


4890 


3 


2.3 


4893 


4896 


4899 


4901 


4904 


4906 


4909 


4911 


4914 


4916 


3 


2.4 


4918 


4921 


4923 


4925 


4927 


4929 


4931 


4933 


4935 


4936 


2 


2.5 


4938 


4940 


4942 


4943 


4945 


4946 


4947 


4949 


4951 


4952 


2 


2.6 


4953 


4955 


4956 


4958 


4959 


4960 


4961 


4962 


4964 


4965 


1 


2.7 


4966 


4967 


4968 


4969 


4970 


4970 


4971 


4972 


4973 


4974 


1 


2.8 


4975 


4975 


4976 


4977 


4978 


4978 


4979 


4980 


4981 


4981 


0.5 


2.9 


4982 


4982 


4983 


4983 


4984 


4984 


4985 


4985 


4986 


4986 


0.5 


3 


4987 


4991 


4993 


4995 


4997 


4998 


4999 


4999 


4999 


5000 




00 


5000 























Table A, which is quoted from page 55 of Davenport's ' Statistical 
Methods,' enables one to calculate easily the probability of any given varia 



API'KMUX 



1G9 



tion in a normal distribution or the amount of a variation of any given fre- 
quency (reckoning,' from a stated percentile fjrade) provided the standard 
deviation of tlie distrit)ution is known. The prolmbility of any j,nvcn deffree 
of unreliability of any incasiirt' of a distribution can be calculated from the 
same table provided the mean square error of tlie measure jh known. 

Table B, which is quoted from paj^'e 203 of Galton's ' Natural Inheritance,' 
serves the same purpose %vhen the probable error is used in place of the 
standard deviation ami mean square error. To make it comparable with 
Davenport's table tlie entries should be halved. 



TABLE B. 

TABLE OF VALtT-^S OF TIIK .NORMAL PROBABILITY I.NTKCKAL CORRE.SPONDING TO 

2z 

VALUES OF ; OK TIIK FRACTION OF TIIK AUKA OF TIIK ClUVK 

P. E. 

J- Z —" X 
BETWEEN TIIK LIMITS AND . 

P.E. P. E. 

Total area of curve afisinned to be 1. 
x = deviation from mean. 
P.E. ^ probable error. 



Multiples of the 






















Probable 


.0 


.1 


O 


.3 


.4 


.6 


.6 


.7 


.8 


.9 


Error. 

























.00 


.065 


.11 


.16 


.21 


.26 


.31 


.36 


.41 


.46 


1.0 


.50 


.54 


.58 


.62 


.66 


.69 


.72 


.75 


.78 


.80 


2.0 


.82 


.84 


.86 


.88 


.89 


.91 


.92 


.93 


.94 


.95 


3.0 


.957 


.964 


.969 


.974 


.978 


.982 


.985 


.987 


.990 


.992 


4.0 


.9930! .9943 


.9954 


.9963 


.9970 


.9976 


.9981 


.9985 


.9988 


.9990 


5.0 


.9993 .9994 


.9996 


.9997 


.9997 


.9998 


.9998 


.9999 


.9999 


.9999 


infinite 


1.0000 



















A1TE.\I»IX III. 

Suggestions fob lN\Ti:sTiriATioNs in Educational Science. 
It is often as profitable fo learn what oupht to be and can W, as what has 
been, found out about any body of facts. I therefore make no npologj' for 
the addition of this chapter. 

1 lir problems that will be suggested are such as any trained studf-nt who 
possesses ingenuity and a knowledge of elementary stntistics can attack with 
fair promi,se of success. 

The Disrovrri/ of Uuitit of Mrulnl Mrnaurriuiut . 

Educational science needs lists of words in spelling, of examples in arith- 
metic, algebra and geometry, of qucstion« in geography, history and grammar, 
exercises in Latin, French and German, etc., 80 chosen that any one will l>o of 
approxiniatcly the same difTiciilty as any other, or at least so that a given 
group of two or three or four will be of equal dilTiculty with other given 
groups. The service rendered to physical science by the inch, the ounce, 
the ohm. the ampere, the calorie, etc., should Iw duplicated in mental »cienc«. 



170 EDUCATIONAL PSYCHOLOGY 

Such commensurate units of measurement may be at least roughly determined 
by taking as equal those tasks which are done by equal percentages of a 
group of individuals in a constant time. Thus if with the examples printed 
below, out of 1,000 eighth-grade children chosen at random 761 do example 1 
correctly in 1 minute and 759 do example 2 correctly in the same time we may 
say with fair surety that accomplishment of 1 equals accomplishment of 2. 

1. How much is I + f — f + f — I ? 

2. How mucn is |6XffXf|Xi|? 

3. How much is |i X *t ^ -"/- X ^s ? 

4. To I add f ; divide by ^f ; add if^ ; multiply by |. 

If we find a score of examples for all of which the percentages of correct 
answers are practically identical we can say, for eighth-grade children 
1 = 2::=3 = 4 = 5 = 6 = 7 =8^9, etc., and use all the examples as dupli- 
cates of a common unit, just as we use all inches or ounces. 

Until we have such units all our investigations rest on insecure founda- 
tions. 

The Distribution of Mental Traits. 

Arguing from the average condition instead of from the total con- 
dition of affairs is a well-nigh universal fallacy in educational theory. For 
instance, the average income of the American universities and colleges for 
men and for both sexes listed in the '99-1900 report of the U. S. Commissioner 
of Education was about $50,000; yet there were only 10 per cent, of the 
colleges which had within $15,000 of that amount. A foreigner knowing 
nothing of conditions here would never imagine that 37^ per cent, of these 
so-called colleges had less than $10,000 income per year, nor that we pos- 
sessed colleges with an income twenty times the average. 

Only in a few cases do we know the exact distributions of the facts about 
which we argue. Yet nothing is needed beyond time, thought and energy 
to discover the distributions of — 

The age of entrance to school; 

The age of leaving school; 

Length of attendance upon school; 

The age of college graduation; 

The ability of children of any given age or amount of training in any 
form of school work that can be measured in units of amount, e. g., 
spelling, arithmetical work, reading, writing; 

The cost per pupil for elementary education; 

The cost per pupil for secondary education. 

These and many other variable facts have not been fully described and 
measured but they could be from records available in reports or in superin- 
tendents' offices or from tests easily made. 

The Relationships of Mental Traits. 

(1) Almost any measurement of relationships is important from the 
point of view of general psychological theory. (2) Measurements of the 
relationships between school abilities by means of objective tests are needed 
to compare with the results found in the case of the teachers' marks. (3) 
Measurements of the relationships of various simple tests to more complex 



APPESDIX 171 

and general abilities will help us to diagnose the pcneral conditions more 
easily. For instance, we may expect some time to find eight or ton tests 
capable of being given in an hour or two which will inform us precisely of a 
pupil's degree of mental maturity. (4) Tlie relationships of success in the 
early years of school to success in later years, of success in school to hucccbs 
in life, and of early ta.stes to later career, are of the utmost practical im- 
portance. Yet the record books of a single school system and the school murks 
of 200 adults wliose relative success in life was roughly known would pro- 
vide answers to the first two questions and a moderate amount of investiga- 
tion of the boyhood of selected adults would go far toward answering the 
third. 

Original and Acquired Traits. 

A comparison of the variability in school abilities of orphans brought 
up in an institution under the same rules, with the same habitat, etc., with 
children of the same general social group brought up in a variety of homes 
with different ideals, models and requirements inlluencing them. Such a 
study well done would be worth thousands of pages of opinion about home 
training or the potency of the germ plasm. 

A comparison of the similarities of identical with those of unlike twins. 
In both cases we have for the two members of each pair clo.sely similar 
training. Consequently whatever greater similarity is found in the identical 
twins must be due to original nature. 

Measurements can be easily ol)tained of the following traits: 

Grade reached in school, 

School marks. 

Musical ability, 

Athletic ability. 

Handwriting, 

Rate of reading. 

Rate of writing, 

Spelling, 

Addition, 

Multiplication, 

A test (give 00 .seconds time), 

a-t test (give GO seconds time). 

Other simple tests can be readily devised. 

Heredity. 

The exact study of family re'<emblancc8 is statistically somewhat intri- 
cate, but the collection of records of mental traits in related individual."! 
which a trained statistician may later subject to careful examination is a 
useful and interesting study. 

For the student of the nicntiil progress of the race i>erhap» the most 
important question of all cr)ncernH the correlation bit ween fertility (or more 
e-vactly reproductivity) and intellectual and moral traits. Tlie corndation 
in women between fertility and stature is for mothers and daughters .18. 
This is sufTicienl to bring about a sensible increase in the stature of the 
race in a century. In si> far as intellectual gifts and moral virtues arc corre- 
lated with fertility we have surety of rariul progress apart from any action 



172 EDUCATIONAL PSYCHOLOGY 

of natural selection in the strict sense. The exact treatment of this ques- 
tion needs much statistical care, but the collection of the statistics of mar- 
riage and offspring in the case of individuals of known mental makeup is not 
difficult. One of the most useful contributions to education in the broadest 
sense would be a document presenting such figures for ten or more individuals 
chosen at random from the following groups : bishops and high church officers, 
clergymen of fifty years and over who have remained undistinguished by 
large salaries, published writings or great esteem for intellect amongst their 
fellow clergymen; bankers, heads of factories, heads of commercial enter- 
prises, small grocerymen and butchers, clerks, janitors; judges of the su- 
preme court of the United States, eminent lawyers of lower courts, profes- 
sors of law in universities, petty lawyers in country towns; members of 
cabinets, senators, congressmen, members of state legislatures, small office- 
holders in cities; professors in universities, teachers in high schools, book- 
keepers; superintendents of factories, foremen of construction gangs, build- 
ers, carpenters and other mechanics, unskilled laborers. Though the sta- 
tistics are still more important in the case of women it is harder here to 
measure intellect by achievement. It should, however, be easy to rank in rough 
order for intellect a hundred women whose work or households or per- 
sonalities were well known to the observer. Notes of relevant facts in each 
case would make the facts capable of treatment later. 

The Influence of the Environment. 

Although, as was noted in the text, it is difficult to get two groups, one 
characterized by the presence, the other by the absence of a given training 
and still have the condition of the groups before the training alike, still it is 
possible with proper care to get such groups with and without kindergarten 
training; with the trainings of a 3-, a 4- and a 5-hour session; with 
coeducation and with separate classes, etc. 

The influence of special forms of discipline upon more general capacities 
and habits can be studied with advantage in the case of almost any function. 

The Influence of Selection. 

If the members of the grammar school population of the age of twelve 
or thirteen were measured for intellect, for social position of parents, for 
physique and for any other traits of importance and if later it was noted 
which of them went to high school we should know how far the high school 
has the pick of the intellect or of the wealth or of the physique or whatever 
the trait might be, of the general population. If we recorded these same 
facts again in the first year of high school and then noted which ones 
graduated we could tell the extent to which high-school graduation means a 
particularized selection. So also by following groups to college and to pro- 
fessional schools. The result of a careful tracing of a thousand children 
from the last year of compulsory attendance up through the higher schools 
would to my mind be one of the most brilliant reports in educational literature. 

Mental Growth. 

Although almost any repeated measurements upon children would be 
worth while, the precautions necessary to avoid a mixture of practice effect, to 
get tests suited for use over a period of years, and to treat the problems of 



API'EXDIX 173 

measurement of change adroitly, are so numerous that the student should 
have thorough training in making mental measurements and in their statis- 
tical treatment. 

Sex Differences. 

The comparative variability of adult men and women is not known 
with anything approacliing completeness or precision. College students in 
colleges where men and women students are selected from groups of the 
same intellectual quality will otter an abundance of material. Their marks 
in college courses and their abilities in mental tests can be readily ascer- 
tained. DitTcrences in the amounts of various abilities can be measured at 
the same time. In the case of school children the results stated in Chapter 
XI. need to be confirmed or replaced by more accurate ones. 

The investigations suggested above are only a few samples of the hun- 
dreds of promising studies that await him who chooses to study the facta 
at first hand. They, rather than others, have been chosen for mention 
chiefly because of their practicability and freedom from excessive requirement 
of technical psychological training. 



INDEX. 



Abnormal mental conditions, 22, 
121if. 

Abstraction, power of in defectives, 
133f. 

Acquired traits, inheritance of, 62ff. 

Addition, 33, 39, 115, 117. 

Affectability of women, 120. 

Age, changes in mental traits due to, 
97ff. 

AiKiNS, H. A., 34. 

Algebra; see School marks. 

Arithmetic, the influence of school 
methods on, 72ff; relationships of 
different features of, 39 ; relation- 
ships to other studies, 37f. 

Arm-span, inheritance of, 55. 

Arrest of development, 140f. 

Artistic faculty, inheritance of, 54. 

Association of attributes, means of 
measuring, 26. 

Associative processes, inheritance of 
types of, 55; in defectives, 133f.; 
sex differences in, 115, 117. 

Bagley, W. C, 148, 149. 
Bair, J. H., 92. 
Boas, F., 139, 146. 
Brinckerhoff, E. B., 37. 
Brothers, resemblances of, 50ff. 
Brown, E. M., 86. 
BuRRis, W. P., 35f., 56ff. 

Causation, of correlations between 
physical and mental traits, 144f. ; 
of differences between age groups, 
lOOf. ; of differences between sex 
groups. 111. 

Cephalic index, inheritance of, 51, 54. 

Chicago Department of Child 
Study, 146f. 

Classification, of exceptional condi- 
tions, 121; of mental defectives, 
128f. 

Coellicipnts, of correlation, 25f. ; of 
variability, 114. 

Cole, L. W., 114. 

College marks, correlations of, 35; 
sex dilfcrences in, 115, 117. 



Conscientiousness, inheritance of, 54. 
Correlation, coefficients of, 25f., 49f. ; 

see also under relationships. 
Cross education, 86ff. 
Davis, W. W., 87. 

Deafness, inheritance of, 51. 

Defectives, in general, 125ff. ; classi- 
fication of, r28f. ; measurements of, 
130ff. ; moral, 135f. ; training of, 
127, 129f. 

Deformities of body, influence on in- 
tellect, 147. 

Development, arrested, 140f. ; see 
also under Growth. 

Differences, mental, means of measur- 
ing, 116. 

Discipline, formal, of the mind, 81ff. 

Discrimination, delicacy of, changes 
due to age, 97ff. ; in defectives, 
133f. ; sex differences in, 115, 117. 

Distribution of mental traits, 13ff. ; 
investigations of, 170; multimodal, 
17; skewed, 18f. 

Drawing, relationships of to other 
studies, 36f. 

Earle, E. L., 52, 114. 

Elimination of pupils from the school 

system, 94ff. 
Ellis, H., 119, 120, 150. 
Eminence, inheritance of, 53. 
English; see School marks. 
Environment, amount of influence, 

6Gff. ; investigations of, 171f. ; 

method of action, 77ff. ; vs. original 

nature, 40ff. 
Exceptional mental conditions, 22, 

r21ff. ; classification of, 121 f.; in 

rate of growtli, 13Gff. 
Eye color, inlicritance of, 50, 55. 

Faculty psychologj', 29 f. 

Fallacy of selection, 60, 93f., lO.'Jf., 

11 If., 1.38, ir)8ff. 
Fatigue, changes due to age in, 99. 
Fay, E. a., 52. 
Female mental traits; sec Sex difTcr- 

cnces. 



175 



176 



INDEX. 



Fluctuations in mental growth, 107f. 
Forearm length, inheritance of, 55. 
Formal discipline of the mind, 80if. 
Formulae for mental measurements, 

166flf. 
Fox, W. A., 39, 114. 
Fracker, G. C, 88f. 
French, relationships of to other 

studies, 35f. 

Galton, F., 18, 42, 43, 44, 49, 53, 54, 
59, 60, 145. 

Geography; see School marks. 

Geometry; see School marks. 

German; see School marks. 

Gilbert, J. A., 88f., 97ff., 114, 146, 
149, 150. 

Greek; see School marks. 

Growth, mental, exceptional rates of, 
136ff. ; fluctuations in, 107f. ; in- 
vestigations of, 172; sex differences 
in, 109; slow, 139f. ; specialization 
of, 105ff. 

Hair color, inheritance of, 51, 54. 
Height; see Stature. 
Heredity; see Inheritance. 
History; see School marks. 

Immaturity, tests of, 140. 

Individual differences, 22. 

Inheritance, mental, 47fF. ; alternate, 
blended and creative, 57ff. ; laws of, 
59ff. ; means of measuring, 49f.; 
physical basis of, 61 ; specialization 
of, 59f. ; of acquired traits, 62ff. 

Instincts, of sexes, 118f. ; relation of 
to inheritance of acquired traits, 
64. 

Intelligence, inheritance of, 54. 

Investigation, topics for, 169ff. 

James, W., 88. 
Jennings, H. S., 48. 
Johnson, G. E., 130, 148. 
JuDD, C. H., 89f. 

Lancaster, G. E., 153ff. 
Latin; see School marks. 
Learoyd, M. W., 120. 
LoEB, J., 63. 

Male instincts, 118f. 

Marks, school; see School marks. 

Mathematics; see School marks. 



Measurement, by relative position, 
4f.; formulae for, 166ff.; of change, 
lOlflF. ; of differences between 
groups, 116; of groups, lOff.; of 
heredity, 49f.; of relationship or 
resemblance, 24flf., 49f.; of re- 
liability, 8, 12; of variability, 7f., 
lOf., 114; units of, 4, 169f. 

Memory, changes in due to age, 97flf.; 
in defectives, 131ff.; sex differences 
in, 115flf.; training of, 88. 

Morality, defects in, 135f.; and 
original nature, 45. 

Morris, G,, 37. 

Motor ability, changes in due to age, 
99; in defectives, 13 Iff.; inherit- 
ance of, 57; relationship of to 
mental ability, 148ff.; training in, 
92. 

Multiplication; see School marks. 

Nervousness, and mental ability, 147. 
NoBSWORTHY, N., 57, 132, 143. 

Original nature, defined, 40; influence 
on mental traits, 40ff,; investiga- 
tions of, 171. 

Parker, S. C, 36f. 

Pearson, K., 26, 54, 59, 61. 

Perceptive processes, ability in, in- 
heritance of, 55f. ; in defectives, 
133f. ; sex differences in, 115flF.; 
training of, 90ff. 

Physical traits, inheritance of, 50f.; 
relationship of to mental traits, 
142ff. 

Popularity, inheritance of, 54. 

Porter, W. T., 145. 

Practice, influence on general abili- 
ties, 80flf. 

Precocity, 137flf. 

Prescott, I., 143. 

Primitiveness, of female, 120. 

Pulse, in defectives, 133f. 

Questionnaire methods, 152ff. 

Kates of growth, exceptional, 136flf. 
Reaction time, changes in due to age, 

97ff. ; sex differences in, 115ff. ; 

training in, 89ff. 
Relationships, means of measuring, 

24ff., 49f. ; of body temperature to 

mental ability, 143; of mental and 



IXDEX. 



17 



physical traits, 142ff. ; of mental 
traits, investigations of, ITOf. ; of 
motor ability and intellect, HSfT. ; 
of precocity to later achievement, 
138; of school abilities, 35fT. ; in 
college subjects, 35; in elementary 
school subjects, 37; in high school 
subjects, 36f . ; of stature with in- 
tellect, 145fr.; table of, 31 tT. 

Resemblance, measurements of in re- 
lated individuals, SOfT. 

Rhetoric; sec School marks. 

Rice, J. M., 52, 68flf. 

School marks, abilities shown by, in- 
heritance of, 56; relationships of, 
35ff. ; sex dififerences in, lli^fT. 

School methods, influence of, on 
arithmetic, 72fT. ; on arrested de- 
velopment, 141 ; on spelling, 68fT. 

Science; see School marks. 

Selection, fallacy of, 66f., 93, 103f, 
11 If., 138, l.'/sfT. ; influence of, on 
distribution, 18f. ; on individual de- 
velopment, 77f. ; on investigations of 
growth, 103f.; of sex ditTerences, 
lllf.; of exceptional children, 138; 
investigations of, 172. 

Self consciousness, inheritance of, 54. 

Sex dififerences, causation. 111; in 
abilities, llGfiT.; in growth, 109; 
in interests, llOf. ; in variability, 
112fT. ; investigations of, 173. 

Shyness, inheritance of, 54. 

Sickliness, relation.ship of to mental 
ability, 147. 

Sisters, resemblance of in mental 
traits, 55fT. 

Skewness of distribution, 18f. 

Slow growth, 139f. 

Smith, A. G., 37. 

Smith, T. L., 86. 

Special training, influence of, in dis- 



crimination, 90f . ; in memory, 85; 
in j)erccptive processes, OOf. ; in re- 
action time, 88f. ; in Bensory-motor 
habits, 92. 

Si)ecialization, of growth, lOofT., 139; 
of heredity, 5!)f. 

Spelling ability, influence of school 
methods on, OHfl". ; inheritance of, 
51; se.x dilFercnces in, 11511. 

Stature, inheritance of, 50; of de- 
fectives, 132f. ; relationship to 
mental ability, 14.3(1. 

Stumpf, C, 87. 

Suggestibility, change in due to age, 
97f. 

Superiority, exceptional, 12311. 

Temper, inheritance of, 54. 
Temperature of body, in defectives, 

133f. ; relation of to mental ability, 

143. 
Tests of mental abilities, 140, lG5fT. 
Thomas, W. S., 96. 
Thorndike, E. L., 34, 37, 39, 90f. 
Time of reaction; ace Reaction time. 
Transmission of acquired traits, 62fT. 
Transmutation of measurements by 

relative position, 19fT. 

Variability, of sexes, 112flr. ; reduction 
of in relatc<l individuals, 49; thf> 
measurement of, 7, 11 fT., 114. 

Vivacity, inheritance of, 54. 

VOLKMAN, 86. 

Warner, F., 137, 147, 148. 
Weight, and intellect, 145; of de- 
fectives. 133f. 
West, G. M., 146. 
WiSSLER. C, 34f. 
Woodward, C. M., 95. 
WooDWORTH, R. S., 87, 90, 91. 

Vi LE. c;. U., 26. 



/ 



[r 



